Notes from the North: Snow and Ice

It's been icy cold in the far northlands, with temperatures hovering not too far above zero for several days. The snow isn't really all that deep, only 8 inches in the back yard, but it's covering everything and hanging fairly heavy on the trees.

Snow on black spruce.

Looking upward, we can see ice crystals frozen on to the needles.

It was about 3°F when I was out taking these photos.

Brr!

Ice crystals on the twigs of a deciduous tree.

Ice is a mineral of the hexagonal crystal system. The crystals in this photo consist mostly of needles and plates, probably a combination of of soft rime ice and hoarfrost.

I'm hoping for some sun today so I can take more photos of the ice-laden trees.

Death Valley Trip, Getting There: Coaldale, Black Rock, Lone Mountain, and the Boss Mine

Onward! Onward! How far will we get this time?

Coaldale, as seen in August, 2010.

With Boundary Peak still in view, MOH and I rounded the corner at Coaldale Junction, and pulled in briefly at Coaldale. This particular ghost town, which was first a small mining town and later a roadside waystation with a tiny population, holds a few minor memories for me, dating back to my early days at Northern Exploration Company in the late 70s and early 80s. For some reason, it always seems like a depressing place to stop, and I can rarely bring myself to take a photograph or to get out of my vehicle to take a close look. This time was no different, so I've uploaded a photo I shot back in 2010.

A few miles on, we pulled in at Black Rock, a spot which may originally have been just a little prospect pit in some black chert of the Ordovician Palmetto Formation, but which is now a semi-convenient place to stretch your legs (although it doesn't really offer much cover as a pit stop, and the Millers rest area and the town of Tonopah aren't too much farther down the road).

Coming to Black Rock from the west, Google Street View.

Lone Mountain as seen from Black Rock, looking ESE.

From the south side of Black Rock, we had a good view of Lone Mountain beyond the playa and salt flat of the southwestern end of Big Smoky Valley. A tiny bit of the Weepah Hills is in shadow off to the right (west).

A closer view of the southwest to northwest side of Lone Mountain.

In this photo, the lighter colored rock formation toward the right (west) is the ЄpЄ Reed Dolomite, which, as I noted earlier, is usually listed as Precambrian or Precambrian to Cambrian, and sometimes as Cambrian only. Here it's on top of a thin, dark section of Precambrian Wyman Formation. Underneath the Wyman, and to the left (east), the Cretaceous Lone Mountain pluton forms the bulk of Lone Mountain.

A couple ways in which the Cretaceous may have intruded the Precambrian so sharply and neatly are developed by Maldonado (1984) in the explanation of his map of the Lone Mountain area. I personally think the contact is structural: a low-angle fault (detachment, anyone?), and, in fact, the area is noted as being part of the Silver Peak-Lone Mountain detachment system (Oldow et al, 1994) or Silver Peak-Lone Mountain extensional (or core) complex (Oldow et al, 2009). Also, this map shows the contact as a detachment fault  (Hulen, 2008, between pages 4 and 5). In the few places that I've seen the Wyman-pluton contact on Lone Mountain, I've noted shearing, faulting, or other complexities—and along the north and west side of Lone Mountain, the top of the pluton looks somewhat planar from a distance, and other planar features (jointing?) are apparent from some angles. If you're driving by, a good place to pull off to see these planar features (I'm really not sure what they are) is at the turnoff to the dirt road going to the northern Gilbert mining district a few miles east of Black Rock  (Google Maps location).

Google Earth image from the perspective of between Black Rock and the turnoff to the northern Gilbert district, and up in the air a bit.

Approximate mapped contacts of the three major rock formations, from Maldonado, 1984.

The same image with a few pink lines added.

I'm not sure what the pink lines represent, other than that they are supposedly entirely within the Lone Mountain pluton. They may be joints in the pluton; they may be Tertiary lamprophyre dikes, as on the 1984 map. Another possibility is that the intrusive-sedimentary contact is mixed, like it is on Mineral Ridge, where Wyman and intrusive rock alternate near or just below the detachment fault (or detachment faults). Or maybe all three possibilities come into play. These are just a few ideas to take with you if you happen to go hiking in the area.

Turning back toward the highway, I stumbled across a few interesting rocks.

Breccia.

The rock is a veined and brecciated chunk of Ordovician Palmetto Formation—chert or siliceous mudstone to siltstone. While walking around, I wondered what the remnant of an old mine dump was all about. Maybe this rock holds a clue.

Here's a zoomed in view of the same rock, focusing in on the quartz vein right and center.

The quartz vein contains brown blades of a relict mineral that has now gone to iron-oxide and silica. Possibly the mineral was calcite, and if so, the resulting mineral or texture is often referred to as "bladed quartz" or "bladed quartz after calcite," or more properly, "quartz [or silica] after bladed calcite." The texture can be indicative that you're in the right part of an epithermal system to find an economic gold or silver deposit. Most of the quartz after calcite I've seen has been crystalline; this silica is microcrystalline.

In fact, several smallish gold deposits have been found in the immediate area, and one has been mined (so far only one deposit has been considered economic).

The Boss mine, a small gold deposit mined in the late 1980s, can be seen just across the road from Black Rock.

A zoomed-in view of the open pit area of the Boss mine.

The Boss produced about 32,000 ounces of gold from 600,000 tons of ore (Diner and Strachan, 1994). That would mean the ore grade was about 0.053 ounces Au per ton (o.p.t). The other deposits, including the Black Rock zone, are described here and here, along with the geology of the Boss mining area. Gold is reported to occur mostly in both Tertiary rhyolites and andesites.

And that will be it for today!

Location map

Related Posts (in order of posting):
Death Valley, "Super" Blooms, Turtlebacks, and Detachments
Death Valley Trip, Part 2: More of the Badwater Turtleback Fault
Death Valley Trip, Part 3: Northward, and over Daylight Pass
Death Valley Trip, Getting There: Wave Clouds beyond the Sierra
Death Valley Trip, Getting There: A Hike to Pleistocene Shorelines

Death Valley Trip, Getting There: Walker Lake, Road Stories, A Bit about Copper, and Some Folds near Luning

Death Valley Trip, Getting There: A Jeep Trail, Folds and Cartoons of Folds, Even More Folds, and Boundary Peak

Death Valley Trip, Getting There: Highway 95, Redlich, Columbus Salt Marsh, and Another View of Boundary Peak

Selected References:
Diner, Y., and Strachan, D.G., 1994, Geology of the Boss mining area, Gilbert district, Esmeralda County, Nevada: Econ. Geology v. 89, no. 5, p. 1176-1182.

Hulen, J.B., 2008, Geology and conceptual modeling of the Silver Peak geothermal prospect, Esmeralda County, Nevada: unpublished report for Sierra Geothermal Power Corporation, 23 p.

Maldonado, Florian, 1984, Bedrock geologic map of the Lone Mountain pluton area, Esmeralda County, Nevada: U.S. Geological Survey Map I-1533, 1:24,000.

Oldow, J.S., Elias, E.A., Ferranti, Luigi, McClelland, W.C., and McIntosh, W.C., 2009, Late Miocene to Pliocene synextensional deposition in fault-bounded basins within the upper plate of the western Silver Peak–Lone Mountain extensional complex, west-central Nevada: Geological Soc. America Special Papers 447, p. 275-312.

Oldow, J.S., Kohler, Gretchen, and Donelick, R.A., 1994, Late Cenozoic extensional transfer in the Walker Lane strike-slip belt, Nevada: Geology v. 22, no. 7, p. 637-640.

Strachan, D.G., 1988, Economic geology and exploration potential of the South Boss prospect, Boss gold mine, Esmeralda County, Nevada: unpublished report on file at Nevada Bur. Mines and Geology, 11 p. and notes.

Seeing Geology in Patterns

"This month’s Accretionary Wedge topic is “Seeing Geology Everywhere.” Like many geologists, I often see geology in places where there are no rocks. ...

"Do you see geology in unexpected places? Do you often find yourself viewing the world through geology-tinted glasses? Do you have any adorable cat pictures that could be used to illustrate geology?"

     – Evelyn Mervine, Accretionary Wedge #57 call for posts.

Stucco plaster wall texture by Sherrie Thai, some rights reserved.

It began a long time ago: maybe I was about 8 or 10 years old, and I'd stare at the wall next to my bed when trying to sleep. I'd see land masses or continents in the wall texturing, something that perhaps came from my early love of maps and globes, which naturally showed countries and continents. In fact, my brother and I had played a game in the back yard on lazy summer days: while looking up at the afternoon cumulus clouds passing by, we'd name them as though they were foreign or alien land masses of the sky. And then we would play a form of the floor-is-lava game, wherein we'd have to jump from the shadows of the cloud continents in order to not fall out of the sky (because we'd be imagining ourselves on the clouds, not on the ground).

What happens now most commonly, is that I'll be working on some geological problem or project, and I'll start seeing textures or patterns related to certain rocks or maps in floor tiles, walls, trees, clouds, or anything else that happens to resemble some geologic texture or map pattern.

Recently, having spent a lot of time looking at certain hydrothermally altered rocks, I noticed this floor texture that appeared nearly identical to a patchy quartz-sericite alteration style with irregular to wavy chloritic seams.

Enlargement of floor pattern.

Then, while taking photos of clouds the other morning, I noticed this pattern that reminded me of a vein with horsetail structure.

Cloud picture with added lines.

And finally, I often notice a color in the clouds that reminds me of the anomalous Berlin blue birefringence color typical of certain chlorite minerals.

Rock Color Links

Here are a few links I find useful in comparing RGB, HEX, and UCL or Munsell colors, though these don't all match the original Rock Color Chart, which is no longer available. The new Rock Color Chart colors do not match the old chart completely, and is organized in a way that I find difficult for real world use.

Geological ROCK-COLOR CHART - online pdf version (new)

The original - no longer available, though QCQA says, "Discontinued...Check with us later," and "Usually ships within 24 hours" — NOT.

RGB Chart & Multi Tool: HEX, RGB, Munsell.
Universal Color Language, Level 3: Munsell and HEX.
NBS/ISCC Color System: Munsell and HEX

Color Theory: Completed Munsell Color Charts - Gnomicon blog - 5R page.

http://colors.bravo9.com/nbs-iscc-rc-rock-color-chart/swatch/: This site is *still* down (permanently?), and my notes don't tell me what it was.

More About Colors:
Color-Name Dictionaries

Robert Krimen > Color-Library

Also:
The Michel-Lévy Interference Color Chart - although the colors look a little washed out

Tremolite-Actinolite Skarn

A few days ago — after recovering from an average long work stint by relaxing, walking, visiting, helping to lay flooring, and running errands while at the lake, then returning to our little house via Costco and a family meal or two in the big city we sometimes drive through — I wrote a note in an irregularly kept journal indicating that I had been dreaming about diopside skarn and actinolite schist. I understand dreaming about the former: skarns have been invading my territory at work recently, and diopside skarn is one of my favorite types of skarn, introduced to me way back when on the west side of the Inyo Mountains, somewhere near Big Pine, CA. I'm not sure why actinolite schist would pop into my dreaming mind; I haven't worked in those kinds of schists much before. Blueschists yeah, greenschists not so much.

I realized, looking through a batch of rocks lying about our little house, brought from here and there, often from mine dumps, sometimes from close by, other times from places as far away as northeastern Idaho or southcentral Alaska, that I have photos of what I was calling actinolite skarn, but which may really be tremolite skarn. I think the difference might only be apparent by either doing petrography or x-ray work, neither of which will be done on these rocks anytime soon.

So, on with the photos!
The tremolite-actinolite in this skarn is a pale yellowish green, a color my camera seems to want to either distort with too much green, too much blue, or not enough color at all.
The skarn is cut by numerous quartz-calcite veinlets containing pyrite, magnetite, and chalcopyrite. The veinlets are up to a half centimeter wide, usually more like a millimeter in width. Tiny.
The gray, vaguely bluish metallic mineral in the central part of the veinlet is magnetite. The brownish to yellowish mass of sulfides is mostly made of pyirte — you can barely make out a few cubic forms. Some of the shiny golden yellow grains are chalcopyrite. It's hard to say what the pyrite:chalcopyrite ratio is, even when looking at this rock in person.
This photo, especially when enlarged, shows the generally felted look of the fine-grained tremolite-actinolite.
Zooming in a bit, we can see the sheaf-like to radiating crystals of tremolite-actinolite, which are hosted in nearly invisible calcite and are possibly intergrown with other very fine-grained skarn minerals such as wollastonite.
A couple of the larger tremolite-actinolite crystals can be seen near the center of the way zoomed in photo above. The largest of these elongate sheaves is probably no more than a millimeter in length. Fine-grained indeed!

Actinolite is the iron-rich end member of the tremolite-actinolite series. I suspect that these very pale green to white crystals are tremolite. In hand sample, I usually just go by color, prefering my tremolite to be white to clear, but it can be light green, light yellow, brown, and even pinkish.

UPDATE: I've indicated the general area of where I most likely found this skarn rock in the Location shown below.

Report on an Afterwork Field Trip

This will be a brief field trip report from an undisclosed place and an undisclosed time. In fact, other such field trips over the years, whether during or after work, might be worth reporting on occasionally, mostly sans photos.

It was a sunny afternoon, approaching early evening, and several colleagues and I passed by some broken and brecciated road cuts while on the way to our various evening destinations, wherever they might have been. The purpose of the rather spontaneous mini field trip was to shoot the bull about the meaning of the road cuts and see if we could figure anything out—in other words, to get our creative thoughts flowing. Lines and crude cross-sections were drawn in the dirt on the side of the road, with less crude versions drawn in some field books.

Our first stop was essentially a mess of fractured, broken, and shattered rocks showing varying degrees of iron-staining and oxidation. Some jarositic-looking, weakly clayey limestones formed a possibly arched, upper zone above more typically calcite-veined dark gray Devonian limestone cut by hematitic seams and hematitic fracture-fill fines. Discussions ensued about what iron-oxides were staining the rocks and filling in fractures. A reddish coloration—reddish brown to reddish orange brown—in a batch of rocks, sometimes present in broad areas or even over whole mountains, is supposed to be a good sign when one is looking for the upper oxidized to leached portion of a porphyry copper system — at least according to a few old-timers who told me about such things back in the late 1970s when porphyry copper exploration had come to a standstill after what turned out to be a long-term decline in the price of copper.

---

An Aside: A long time ago, Bear Creek or Minefinders developed a color triangle for determining the composition of various limonites or generic to mixed iron-oxides. Powdered pure or nearly pure jarosite (a sulfate containing iron that can form as a weathering or oxidation product of pyrite) was placed in a circlular spot in the upper corner of the triangle, powdered pure goethite was placed in the lower left corner of the triangle, and powerdered pure hematite was placed in the lower right corner of the triangle. Three other circles were placed between the three corners, each composed of 50-50 mixes of the appropriate two of the three main powders, and one circle in the center contained the three end members mixed together. To summarize the triangles main colors, jarosite is pale yellow to white when powdered or scratched, goethite is the typical dark golden brown of the average "limonite," and hematite is its typical reddish brown. I've looked high and low for an online version of this field cheat sheet that consisted of stiff cardboard with clear plastic- or cellophane-covered circles of powders with appropriate labeling, but have yet to find anything resembling the original. Perhaps I'll draw up something similar to the original and go further into this little exercise in crude field determinations sometime at a later date. For now, back to the field trip.

---

I developed a question or two as we were standing beneath the large fractured to brecciated mass of structurally complex reddish to yellowish brown pile of carbonate rocks: (1) were we looking for copper and (2) doesn't the same guide to ore (red rocks and reddish color anomalies) also apply to finding porphyry molybdenum deposits? I also wondered (3) haven't red rocks been considered a guide to ore in at least some disseminated gold districts, for example at and around Florida Canyon? The answers: (1) maybe [seriously, what we were looking for was actually in question], and it is good to define what you are looking for without getting so stuck on what you've decided to look for that you can't see the possibility of finding something else, (2) yes, for sure, something I first learned from other not-quite old-timer types, also back in the late 1970s, and (3) well, of course, but not everywhere.

Our impromptu field trip then moved down the road to stop number two, where a breccia of unknown origin was exposed in a particularly hairy road cut on a tight curve with narrow shoulder and the occasional speeding vehicle. The breccia reminded me of the Titus Canyon megabreccia: mostly angular fragments of dark-colored carbonate rock were cemented by white, crystalline calcite. I thought it looked like a breccia of possible hydrothermal origin, one in which fragments had shattered but not moved far. It also looked a bit like a tectonic breccia, though no faulting surfaces were exposed. The expounder leading this part of our field trip said it could be a collapse breccia that formed over an oxidized massive sulfide deposit. Oxidation of sulfides produces volume loss, leaving a potential collapse waiting to happen. I'm not sure how the calcite gets into position to cement the breccia together, it somehow having to push the fragments apart to exploit the collapsed zone, but some long, thin beds of shaly limestone could be seen to be sagging downward in a couple places, testifying to possible collapse. Perhaps the breccia was really fragment supported instead of apparently matrix supported, in which case the calcite could have moved in later with groundwater or low temperature hydrothermal waters of some kind.

Resulting major questions arose from the two field trip stops and all the bull that was being shot around. One major one that was oft repeated: Should we drill here? Or there? Or over there? Everyone wanted to choose their own drill hole or two and locate them in specific favored spots. Another question: Should we sample here? The answer to that question? If you have to ask the question and don't just pile in with your bags, labels, and rock hammers, the answer is an automatic yes. Conclusion: get on with it! ASAP.

And so ended a spontaneous early evening field trip to two undisclosed field trip stops, along an undisclosed highway, at some vague undisclosed time within the last 10 to 30 years.

---
Torrent, José, and Barrón, Vidal, 2002, Diffuse Reflectance Spectroscopy of Iron Oxides (see page 1441 for Munsell color of some iron oxide minerals).

Somewhat Related Posts:
Some Thoughts on Weirdness, and A Picture (or Two) (or Three)
Megabreccia II: More Photos
Megabreccia III, the Continuing Saga

Salt from Bonneville Salt Flats

Bonneville Salt Flats looking north toward the Silver Island Mountains and Floating Island (small and to the right).

While on our recent trip to Ogden, Utah, MOH and I stopped at the northern of two view-oriented rest stops located on I-80 near the Salduro railroad siding about 8 miles east of the Utah-Nevada border (MSRMaps location). Both rest stops provide good viewing of the Bonneville Salt Flats. From the northern rest stop parking lot you can walk out onto the flats, or at least to the edge of the flats, depending on water level or dryness.

Google Street View at northern rest stop

I didn't walk out very far, just to water's edge. A few other people were out a little farther; someone was collecting salt in large bags, probably for personal use.
A chunk of salt in its native habitat.
MOH brought a small piece of salt home, to add to our mostly unlabeled mineral collection. This is the side with the largest crystals.
Side view of same salt chunk.
View of the opposite side. One of the two sides had encrusted a surface of some kind; I'm not really sure which side was up and which was down.
Salt, more properly known as halite or NaCl, is a cubic mineral.
Cubes on top of cubes.
Tiny cubes.
More cubes.

Halite is a relatively soft mineral with a Mohs Hardness of 2½, meaning that it's barely not scratchable with your fingernail (which is also 2½), but it can be scratched by almost anything else, including a copper penny, a knife, a piece of glass, and steel. Halite tastes salty (surprise!), but not as bitter as the related potassium salt, sylvite (KCl).

Potash (mostly KCl) is mined from the Bonneville Salt Flats, as is magnesium chloride brine, which is used to produce magnesium metal and chlorine gas (for various purposes), and magnesium chloride, which is used as a dust suppressant on dirt roads and for other products.

A Few Links:
Mineral production from the Great Salt Lake

Mining and land speed records come together at Bonneville Salt Flats

View halite with a petrographic scope at Life in Plane Light

Recent Hike: A Feldspar Twin

On a not-so-recent hike, when snow had turned to mud (mud then dried and turned back to deep snow by yesterday), this small and rather unprepossessing rock caught my eye. Perhaps you're wondering why.

One side was glinting at me in the low afternoon light. I reached down and grabbed it, immediately recognizing it as a moderately sizable, though incomplete, orthoclase feldspar, one type of K-spar, with a Carlsbad twin. You can see this type of twinning in a sanidine crystal (sanidine is a related type of K-spar), and read more about K-spars at Life in Plane Light.

A view looking end on at the visible twin plane (above), and with light reflecting off the upper twin (below).

Two views with alternate twins highlighted by the sun, above and below.

I recognized this feldspar as being from nearby intrusive rocks that are often porphyrytic, and which usually contain large phenocrysts of dull pink K-feldspar like this one. Having never seen any exposures of porphyry dikes or masses on our hiking hill, I wonder if this feldspar has eroded from old alluvial fan material that formed from sources now eroded or sources farther up the main canyon than our side of the hill. Either way, it makes me want to look for unmapped porphyry.

Serpentine Post Updated

I just updated my Serpentine: A Group of Minerals post from last summer with some new geoblogosphere links relating to fibrous and asbestiform minerals, including erionite, a zeolite group of minerals that can occur in acicular to fibrous mineral habits. The reason for the update is that the Mineralogical Society of America recently released their Proposed Position Statement on Asbestos, as reported on more thoroughly by Chuck Magee at Lounge of the Lab Lemming and Steven Schimmrich at Hudson Valley Geologist (links below).

• Erionite and Cancer in Cappadocia, Turkey (Olelog, November 5, 2010)


• Guest Post - Naturally Harmful Metals and Minerals (The Geology P.A.G.E., December 29, 2010)


• Concerns over erionite dust as cancer source (Arizona Geology, January 5, 2011)


• Mineralogical Society of America proposes a position statement on Asbestos (Lounge of the Lab Lemming, March 1, 2011)


• Asbestos (Hudson Valley Geologist, March 9, 2011)

I'm particularly amazed that any regulatory agency would use a length:width ratio of 3:1 to describe a mineral as fibrous. Plagioclase would therefore be fibrous much of the time (though certainly not asbestiform), as would these huge cave crystals of selenite.

Serpentine: A Group of Minerals

Last updated 28Apr2013 at 6:35 a.m. PDT

As a property owner in California, and as a geologist, I'm annoyed about the recent BS (SB 624) the state legislature is up to in trying to delete serpentine as the state rock. First of all, as many have pointed out, serpentine is not a rock, it's a mineral group: the Serpentine Group, AKA the Kaolinite-Serpentine Group according to mindat.org (shall we outlaw clay, also?). It is serpentinite (sometimes called serpentine or serpentine rock) that is a rock, the state rock of California – see Serpentine and Serpentinite from the USGS Cascades Volcano Observatory.

Serpentinite, the rock, is commonly formed of antigorite, lizardite, and chrysotile – all of which are Serpentine Group minerals – and other non-serpentine-group minerals such as talc, chlorite, magnetite, magnesite, brucite, chromite, sometimes relict olivine or pyroxene, and sometimes quartz and calcite (usually as later veins). Other mineral associations (for example at New Idria) include montmorillonite, coalingite, hydromagnesite, nepouite, pecoraite, and trace amounts of tremolite. Besides being host to a unique flora that can survive the plant-harsh conditions of high Mg, Fe, Co, Cr, and Ni (along with relatively low amounts of plant nutrients like calcium and potassium), serpentinite bodies in California have been host to most of the state's mineral deposits of chromite, magnesite, and cinnabar, and possibly some of the state's nickel occurrences. Other trace element associations can include minor copper and platinum. Chromium is of the non-hexavalent type (USGS Open-file Report 95-831, Chapter 5).

Asbestos is not a single mineral, and in fact isn't the name of any defined mineral at all. Asbestiform is a particular mineralogical habit that some minerals take: long fibers often in veins or masses. Asbestiform and fibrous, as crystal forms, are similar, with asbestiform being a more extreme version of fibrous. More minerals have a fibrous habit (for example, siderite, malachite, gypsum, celestite, chalcedony) than have an asbestiform habit.

The word "asbestos" comes from the Latin and Greek asbestos, meaning "unquenchable" or "inextinguishable" – also see more about the etymology of asbestos at the Online Etymology Dictionary, at Asbestos: Changing the Name of a Quebec Town, and at Merriam-Webster Online. According to my mineralogy book – the Manual of Mineralogy (after James D. Dana), 21st Edition by Cornelis Klein and Cornelius S. Hurlbut, Jr., 1993 – asbestos minerals in natural form have a length to width ratio greater than 100:1. Also, the book defines the term "asbestiform" as referring to "minerals that are mined for asbestos and possess fibrousity typical of asbestos—that is with small fiber thickness, flexibility, and separability." Not just any old mineral can be called asbestos or be described as asbestiform.

This is what the EPA has to say about asbestos:

Asbestos is the name given to a number of naturally occurring fibrous minerals with high tensile strength, the ability to be woven, and resistance to heat and most chemicals. Because of these properties, asbestos fibers have been used in a wide range of manufactured goods, including roofing shingles, ceiling and floor tiles, paper and cement products, textiles, coatings, and friction products such as automobile clutch, brake and transmission parts. The Toxic Substances Control Act defines asbestos as the asbestiform varieties of: chrysotile (serpentine); crocidolite (riebeckite); amosite (cummingtonite/grunerite); anthophyllite; tremolite; and actinolite.

Five of the minerals listed above that have asbestiform versions are amphiboles: riebeckite, cummingtonite/grunerite, anthophyllite, tremolite, and actinolite. The sixth mineral, chrysotile, is one of the Serpentine Group minerals. The asbestiform version of riebeckite is crocidolite, that of cummingtonite/grunerite is amosite. Anthophyllite is often but not always fibrous, and it is not always asbestiform. The EPA, nevertheless lists the mineral as "asbestos." The same is true for the minerals tremolite and actinolite (two end members of the tremolite-actinolite solid solution series, and to complicate things more mineralogically, both minerals form solid solution series with ferro-actinolite: tremolite–ferro-actinolite and actinolite–ferro-actinolite). Both tremolite and actinolite are commonly found in non-asbestiform habits, and consequently the asbestiform versions are sometimes referred to as "tremolite asbestos" and "actinolite asbestos," which seems to imply, incorrectly, that both minerals are entirely asbestiform.

Are we now going to take all samples of serpentine group minerals and any asbestiform minerals out of circulation, out of all teaching and personal rock and mineral collections? What?? Why? As Lab Lemming says (after pointing out that serpentine can be used for CO2 sequestration and that it prevents earthquakes by allowing faults to creep):

There are 20 forms of serpentine, only one of which is an asbestos mineral. The very dangerous amphibole asbestos minerals specifically mentioned in the bill are completely unrelated to serpentine.

The uproar about serpentinite, the rock, needs to die down: the legislature needs to back off. Otherwise one might think that the legislature was getting ready to fund the state of California (and themselves?) through litigation, rather than by any legitimate means.


GeoBlogosphere - Blogosphere Reports and Photos:
Photo of serpentinite (About.com: Geology - Metamorphic Rock Types gallery)

Monday Mineral: Serpentine (Outside the Interzone, January 19, 2009)

The Other California: Geology and our State Symbols (Geotripper, December 2, 2009)

Rock 365 : Day 74 : Serpentine #365photos (hypocentre's posterous, March 16, 2010)

The Other California: A Journey to the Center of the Earth (kind of...) (Geotripper, March 31)

Dire Threat to Benign State Rock (Updated) (About.com: Geology, June 19)

Unreasoned Fear of Serpents? We Geologists Need to Be Heard (Geotripper, June 24)

Losing Serpentine as the State Symbol of California? Why not educate instead? (Teaching the Earth Sciences, June 24)

CA SB 624 - Senator Gloria Romero's Bill based on BAD SCIENCE (Justin Zzyzx at The-Vug.com, unknown date)

Serpentinite Under Attack, Part 2 (About.com: Geology, June 30)

Libby and the Serpentine Killers (About.com: Geology, July 2)

Hiking up Big Rock Ridge (Literrata, July 2)

Something Doesn't Feel Right About This: The Serpentine Issue in California (Geotripper, July 2)

In defense of serpentine (Lounge of the Lab Lemming, July 3)

More on the asbestos dust-up (Lounge of the Lab Lemming, July 4)

Throwing the Baby Out with the Bathwater: The Serpentine Issue in California (Geotripper, July 5)

Serpentine – SB 624, Senator Gloria Romero and ADAO (FakeMinerals.com, July 5)

Politics, California and serpentine (Eruptions, July 6)

Save Our State Rock...Serpentine Gets A Bad Rep! (AFMS- American Federation of Mineralogical Societies blog, July 6)

Down with serpentine; or, clueless in California (The Volcanism Blog, July 6)

Fear and Ignorance winning out over Education and Knowledge: Serpentine Bill Sailing on through Legislature (Geotripper, July 7)

First Of All, California, It’s Your State Rock And It’s Called Serpentinite (Maitri's VatulBlog, July 7)

California Senate to drop Serpentine as state rock because of asbestos ties (Halfway to Concord, July 8)

Throwing the Baby Out with the Bathwater: The Serpentine Issue in California (Geotripper at Daily Kos, July 9)

A Letter to Governor Schwarzenegger and the California Legislature...About Serpentine!?! (Geotripper, July 9)

Wow...If I had a press secretary, would my assemblyperson call me? Update on the serpentinite issue in California (Geotripper, July 11)

Speak up for serpentine (Oakland Geology, July 11)

California's Unique Serpentinite Landscapes 1 (Geotripper, July 11)

California's Unique Serpentinite Landscapes 2 - And How Education is a Better Choice than a Press Secretary (Geotripper, July 12)

The Law Against Serpentine: The Attorneys' Arena (Andrew Alden, About.com: Geology, July 12)

In praise of green rocks (Active Margin, July 12)

California's Unique Serpentinite Landscapes 3 - Finding Beauty (Geotripper, July 13)

Save our serpentine! (California Dreaming - and the Reality, July 13)

California's Unique Serpentinite Landscapes 4: What can our state rock tell us about geologic processes on Mars? (Geotripper, July 14)

Geology Fail: California Moves to Disown State Rock (Discover Magazine, Discoblog, July 14)

An Introduction to Asbestos, clicks through to the next article (Andrew Alden, About.com: Geology, July 14)

Asbestos in a Nutshell: This miracle material has taught us some lessons (Andrew Alden, About.com: Geology, July 14)

Standing up for serpentinite (Highly Allochthonous, July 15)

A Serpentine-Inspired Rant (Haronic Tremors, July 15)

Serpentine Collecting Spots around California (map by Justin Zzyzx, July 15)

Unscientific California: How Scientific Illiteracy Threatens Serpentine and Biodiversity (Discover Magazine, The Intersection, Sheril Kirshenbaum, July 15, 2010)

California's Unique Serpentinite Landscapes 5: Doing What I Like to Do, and An Invitation! (Geotripper, July 16)

Calling on Californians: West Coast Represent! (Discover Magazine, The Intersection, Sheril Kirshenbaum, July 18, 2010)

California's Unique Serpentinite Landscapes: Eldridge Moores and California's State Rock (Geotripper, July 18)

What California most needs right now -- a defrocking campaign! (Classical Values, July 23)

Serpentinite Adored (Andrew Alden, About.com: Geology, July 23)
SB 624 Senator Romero’s Lies (and more lying liars that tell them) (FakeMinerals.com, July 24)

Fighting For California's State Rock: What's Wrong With Senate Bill 624? (Geotripper, July 25)

Fighting For California's State Rock: What's Right With Serpentine? (Geotripper, July 25)

At home with serpentine (Oakland Geology, July 27)

My Serpentine Letter (Oakland Geology, July 28)

Rock in the limelight: serpentinite (Angelina Souren's Earth Blog, July 29)

My letter opposing SB 624: Serpentin(it)e (Perrykid's Posts, July 29)

An Update on the State Rock Debate in California (Geotripper, August 1)

San Francisco suiseki (Oakland Geology, August 1)

Serpentinite - California's State Rock (Gigapan by Ron Schott, August 1)

The Power of Words: The Debate over Serpentine in California (Geotripper, August 2)

Snaky Words like Serpentinite and Ophiocalcite (Olelog, August 3)

A #CAserpentine photo (Ron Schott, taken May 24, uploaded August 3; click #CAserpentine tag for more photos)

Learn the Facts About Serpentinite Before It’s Removed as California’s State Rock (KQED's Quest Science Blog, Brian Romans, August 5)

Serpentine, Science, and the politics of fear (Talkin' Rocks, August 8)

Save California's State Rock: CGF opposes SB 624 (CGF, Committee for Green Foothills, Greenfeet, August 9)

Standing on a Rock: Why the California Legislature Needs to Hear From Educators, Students and Scientists (Geotripper, August 10)

California Serpentine: To Assembly Member Lieu - A Question of Openness and Fairness (Geotripper, August 12)

Home Sweet Serpentine (KQED's Quest Science Blog, Jennifer Skene, August 16)

The California Serpentine Fight Goes On (Andrew Alden, About.com: Geology, August 19)

Politics of a rock (California's Islands, August 23)

Ding, Dong, SB624 Is Dead (Andrew Alden, About.com: Geology, September 2, 2010)

Erionite and Cancer in Cappadocia, Turkey (Olelog, November 5, 2010)

Serpentinite and mélange (Mountain Beltway, December 25, 2010)

Guest Post - Naturally Harmful Metals and Minerals (The Geology P.A.G.E., December 29, 2010)

Concerns over erionite dust as cancer source (Arizona Geology, January 5, 2011)

Mineralogical Society of America proposes a position statement on Asbestos (Lounge of the Lab Lemming, March 1, 2011)

Asbestos (Hudson Valley Geologist, March 9, 2011)

Maligned Minerals and Serpentinite in Sun (En Tequila Es Verdad, July 31, 2011)

My state’s official rock is a mineral! (En Tequila Es Verdad, Karen Locke, January 11, 2013)

Chrysotile (Sandatlas, March 3, 2013)


More about Serpentine, Serpentinite, and Related Topics:
A Serpentine Haiku: Peter B. Moyle, unknown date.

California State Rock: Serpentine: State Symbols USA.

Klamath-Siskiyou Wilderness Wild and Rugged Sanctuary: California Academy of Sciences – about flora and fauna and serpentinite (among other things).

California Floristic Project: Centres of Plant Diversity, Smithsonian Institution.

North American Serpentine Flora, U.S.A. and Canada: Centres of Plant Diversity, Smithsonian Institution.

Day, D., 2005, Rugged Plants Struggle to Survive on Barren Serpentine Soil: Northern California Geological Society Newsletter, February 2005 [also reprinted here].

Hotz, P. E., 1964, Nickeliferous laterites in southwestern Oregon and northwestern California: Economic Geology, v. 59, no. 3, p. 355-396 [abstract].

Rinaudo, Caterina, Gastaldi, Daniela, and Belluso, Elena, 2003, Characterization of chrysotile, antigorite, and lizardite by FT-Raman spectroscopy: The Canadian Mineralogist, vol. 41, p. 883-890.

Wrucke, C. T., 1995, Serpentine- and carbonate-hosted asbestos deposits, in USGS Open-file Report 95-831.


And Some Other News-Type Items:
Recreation Wrongly Targeted in Clear Creek Closure (Blueribbon Coalition, May 1, 2008)

Several Sierra trails are toxic, group says (San Francisco Chronicle, SFGate, June 23, 2010)

California's state rock raked over the coals (San Francisco Chronicle, SFGate, June 24, 2010)

Why rock this boat? Decertifying the California state rock, serpentine, because it contains asbestos won't alleviate the cancer that the substance causes. (Los Angeles Times, July 28, 2010)

Should California's state rock be stripped of its title because it contains asbestos? (Los Angeles Times, July 2, 2010)

Lawmakers have serpentine rocks in their heads (San Francisco Chronicle, SFGate, July 3, 2010)

Letters to the Editor (San Francisco Chronicle, SFGate, July 3, 2010)

California Looks to Shun State Rock Over Asbestos Content (DailyTech, July 6, 2010)

Is Mother Nature Really Out To Get Us? (Carnegie Forever, July 6, 2010)

Serpentine Politics (Burrito Justice, July 6, 2010)

Dan Walters: California state-rock bill has serpentine agenda (Fresno Bee, July 9, 2010)

What's Underneath the State Rock Bill? More Lawsuit Abuse! (California Civil Justice Blog, July 9, 2010)

Throwing the Baby Out with the Bathwater: The Serpentine Issue in California (Geotripper at Daily Kos, July 9)

Rock stuck in a hard place (San Francisco Examiner, July 10, 2010)

Personal Injury Lawyers Between a Rock and a Hard Place - Lawsuit Industry Picks a Fight With Geologists and Friends (California Justice Association of California - CJAC, July 12, 2010)

State rock debate rocks Twitter The Sacramento Bee, CapitolAlert, July 13, 2010)

Lawmakers want to get state rock off the books (The Oakland Tribune, InsideBayArea.com, Political Blotter, July 13, 2010)

Outcry as State Rock Toppled (The Bay Citizen, July 13, 2010)

California May Drop Rock, and Geologists Feel the Pain (New York Times, July 13, 2010)

California May Drop Its Official State Rock (New York Times, July 13, 2010)

The battle over the California state rock (CalCoastNews, July 14, 2010)

Geology Fail: California Moves to Disown State Rock (Discover Magazine, Discoblog, July 14, 2010)

Calif may dump 'state rock' that contains asbestos (AP, Yahoo! News, July 15, 2010)

Unscientific California: How Scientific Illiteracy Threatens Serpentine and Biodiversity (Discover Magazine, The Intersection, Sheril Kirshenbaum, July 15, 2010)

Geologists take to Twitter to save beloved rock (Mother Nature Network, July 15, 2010)

Lawmakers Look To Change Cancer-Causing State Rock (The Huffington Post, July 15, 2010)

NYTimes, Calif. Press, twitterers too: Big ruckus over state rock serpentine, asbestos activists, and demonization of a stone (Knight Science Journalism Tracker, July 15, 2010)

Geologists protest bill to remove state rock (San Francisco Chronicle, SFGate, July 16, 2010)

Cut and thrust election online (The Sydney Morning Herald, smh.com.au, July 16, 2010)

Wait, they're going after the state rock? (FresnoBee.com News Blog, July 16, 2010)

Political call to 'defrock the rock' (The New Zealand Herald, nzherald.co.nz, July 17)

Lawmaker seeks to defrock 'toxic' official state rock (BBC News, July 17, 2010)

My Word: Rocky stance on serpentine status as state rock (Eureka Times-Standard, July 17, 2010)

My Word: Rocky stance on serpentine status as state rock (The Ukiah Daily Journal, July 17, 2010)

Our Opinion: Between a rock and a hard place (Imperial Valley Press, ivpressonline.com, July 18, 2010)

Calling on Californians: West Coast Represent! (Discover Magazine, The Intersection, Sheril Kirshenbaum, July 18, 2010)

A serpentine approach toward more asbestos litigation (PointofLaw.com, July 18, 2010)

Serpentine rocks on as CO2 vacuum (San Francisco Business Times, July 23, 2010)

Between a rock and a hard place: California’s rock debate (89.3 KPCC, Southern California Public Radio, podcast with Garry Hayes and Brian Wernicke, July 23, 2010)

'Serpentine, Shelly, Serpentine' (El Defensor Chieftan, July 24, 2010)

Geologists Revolt Over Proposal to Change California State Rock (Gawker, July 24, 2010)

Natural Wonders: California state rock in danger of demotion (Chico Enterprise-Record, ChicoER.com, July 24, 2010)

Hamlin: Don't laugh -- this is really important legislative stuff (The Reporter (Vacaville), July 25, 2010)

Californians Debate Fate of Official State Rock (Voice of America, VOANews.com, July 26, 2010)

The irrational fear of our state rock (Los Angeles Times Opinion, July 27, 2010)

Caught between the state rock and a hard place (Stockton Record, Recordnet.com, August 2, 2010)

Ashton: MJC teacher on a mission to vindicate state rock (The Modesto Bee, August 2, 2010)

Why California is between a rock and a hard place (Manteca Bulletin, August 5, 2010)

Serpentine to Avoid Flying Serpentine! (OCWeekly, August 5, 2010)

‘Save the rock’ or ‘Drop the rock’? (The Orange County Register, August 12, 2010)

Editorial: Stop ridiculous debate over state rock (The Oakland Tribune, InsideBayArea, August 13, 2010)

State rock controversy enters new phase (The Sacramento Bee, Dan Walters, August 18, 2010)


Finally:
Signs: "Warning Unsafe To Enter" and "Everything Outside Might Be Dangerous"

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NOTE:

I will be updating the Geoblogosphere and news links as more posts and articles are written.