Friday, July 10, 2009

Links: Blowpipe Tests

Blowpipe analysis - the determination of elements present in minerals by use of a blowpipe - was not taught when I was in school, but was routinely used by geologists of my dad's era. I probably missed learning this skill by only a few years: blowpipe testing was being taught during the early 1950's; it was not being taught where I went to school by the early 1970's.

A bit about the history of blowpipe analysis can be found here, here, and here. Some examples of some old, collectible blowpipe kits can be seen here, here, and through the links on this page. Blowpipe tests are still described in some rock and mineral field guides and in some mineralogy texts - for example, in Dana's Minerals and How to Study Them and in Rocks, Gems and Minerals: Revised and Updated.

For the record, the mineralogy textbook I used in school was probably this one: Dana's Manual of Mineralogy, 18th Edition by Cornelius S. Hurlbut, Jr., 1971; the one I have now is Manual of Mineralogy (after James D. Dana, 21st Edition by Cornelis Klein and Cornelius S. Hurlbut, Jr., 1993 in hardback. If you search the latter book on Amazon.com for "blowpipe tests," you will come up with erroneous results, because the search-inside feature switches to a completely different book (Manual of mineralogy, including observations on mines, rocks, reduction of ores and the applications of the science to the arts, Dana, 1855 - here's the 1876 version at Open Library), not just a different editition as it says. My 1993 edition doesn't mention blowpipes at all!

More Blowpipe Links:
Brush, G. J., and Penfield, S. L., 1906, Manual of determinative mineralogy and blowpipe analysis: Mineralogical Research Company used books with a Flame Coloration by Element table modified from The Manual at Webmineral.com

Elderhorst, W., 1861, A manual of blowpipe-analysis, and determinative mineralogy, Elderhorst: The Internet Archive

Dana, S., and Ford, W. E., 1912, Dana's manual of mineralogy for the student of elementary mineralogy, the mining engineer, the geologist, the prospector, the collector, etc: The Internet Archive

Getman, F. H., 1899, The elements of blowpipe analysis: The Internet Archive.

27 comments:

Lockwood said...

We used Hurlbut and Klein too; I lost my original text when my apartment flooded, but I bought a used copy for 10 or 15 bucks a couple years ago. I can't actually remember if we did a few tests as part of a lab, or if it was "extracurricular" mucking around after lab, but at least a few of my classmates and I did some blowpipe tests. I remember orpiment and realgar were quite easy, but I don't remember which others we tried. I never did get skilled enough to use the oxidizing vs. reducing portions of the flame.

As an aside... not really a blowpipe test, but I have often used a lighter and a pair of tweezer to illustrate to kids on field trips how zeolites, "boiling rocks," got their name. Stilbite is pretty common, and boils real nice. Natrolite is even more common, but just sort puffs up a little. (Natrolite has 2 bound water; I think stilbite has 12)

Silver Fox said...

It's neat you were introduced to blowpipe tests and got to try some out. I'm going to have to check w/ my dad to see if he has a blowpipe kit.

Alaska Al said...

Wow! This makes me feel really ancient. My blowpipe and associated gear were tossed some time ago. Probably in the 1960s.

Silver Fox said...

Hmm... too bad. You could have used it to edyucate us youngsters! You probably didn't realize back in the 1960's that blowpipe kits would be worth money on Ebay someday!

Silver Fox said...

Alaska Al, do you know if blowpipe tests are good for determination of the presence of silver?

Or do you, Lockwood??

Lockwood said...

Not off the top of my head, but a quick google with "blowpipe test for silver" returns some promising results. For example.

Silver Fox said...

Interesting. A reader asked me about testing for silver in the field. The only thing I could think of was blowpipe tests - hence, this post.

So, I encourage anyone interested in more blowpipe test details to do more research than I have (unless more answers show up here in this thread).

Lockwood said...

Here's another. I don't know if the link will take you to the appropriate page, but on page VIII there's an index with assayable elements / compounds, and the pages in the text to find instructions for the assays.

Silver Fox said...

Ooh, that's a neat one! I like the books you can read just like books on the computer.

Lockwood said...

Yeah, it really is. I've just spent some time reading over part of the text- the terminology is archaic, but I'm sure it's figure-outtable if one tries.

Re. the trigger question, I've never actually used this because it seems kind of snarky. If a good friend put me in the right position, I might, assuming that they would see it as a joke. Here's the post where I describe it, here's the home site, and http://lmgtfy.com/?q=blowpipe+test+for+silver you could have sent back. It just seems a little too rude to use, but I think it's very funny.

Lockwood said...

Oops, messed up the last link. It should have read "...and here's the result you could have sent back."

Silver Fox said...

I've been to the "LMGTFY" site before, but thanks for the link. I didn't really know how to find it. (I guess by Googling "LMGTFY") I think it's funny - I've seen it used only on long threads on Scienceblogs where questions are way off-topic from an original post. For questions from readers, I probably wouldn't use it, unless an off-topic question was posted rather than emailed. After all, if I wasn't interested, I wouldn't have looked for the topic myself - but you about know that part. My curious nature just takes over sometimes, then I have lots of links that make a nice post like this one!

And then a knowledgeable or semi-knowledgeable person has to weed out the google entries that are entirely to partly useless and sometimes bogus!

Now will google "knowledgeable" as a spell check.

Rod said...

I guess now that this is actually a thread I can jump in. Thanks for the info on blowpipe possibilities. That didn't occur to me (no training), and I was toying with the idea of microchemical tests that were lightly touched on in a grad-level microscopy course.

What I was actually thinking of was more along the lines of an outcrop test, analogous to the acid/nail trick for copper. That test works pretty well for manganese wads/minerals when they're strongly contaminated with copper. I was wondering whether it would be possible to do a similar test in wad that was contaminated by silver.

Silver Fox said...

Rod, I've never heard of a test like that for silver, but plating copper with HCl, from various Cu-oxide/carbonates and Mn-Cu-oxides like neotosite is fun!

Rod said...

Fun and practical. Fun when it's bright green stuff that you already know is a copper mineral. Practical when it's limonite or manganese wad that has no obvious sign of copper.

As for the "LMGTFY" comment, my experience has been that finding useful information on the web on the things we exploration geos do daily has about the same odds as panning up a gold nugget. Try this, for example. Do a Google search for the acid/nail test for copper, and see how many additional modifiers you have to use before you get anything even close to the test we're talking about.

Silver Fox said...

In the field, the oldtimers I know used hammers, maybe they carried nails also. And sulfuric acid will plate copper out of "live limonite" (copper-bearing, sometimes reddish, glassy-looking limonite) where hydrochloric won't. I've found the nail test to be especially useful for chalcocite, which can occur in very thin coatings around sulfides.

Google often has to be refined several times. The nail test thing is one of the worst, because of copper plating as an industrial process. Now, acid + nail test + copper will come up with this thread, after some bot crawling is completed!

And if you know of work for exploration geos, feel free to email me! :)

Rod said...

I almost always use my hammer, too. You just have to be careful to scour the copper off before you take your next sample for analysis!

Hadn't ever tried the test on simple live limonite, but it seems there's often enough tenorite mixed in to give a positive reaction with HCl.

If I hear of any exploration jobs I'll let you know. Still pretty dead in the Great Basin?

Alaska Al said...

Yes. See Hurlbut and Klien (after Dana) But since the silver minerals are fusible at 1 to 1.5, it is easier to toss the sample into a hot pan and wait for the bright silver residue. Hence the term "frying pan ore."

Rod said...

Huh, that's not exactly an outcrop test, but it might be closer to the kind of practical field test I was hoping to find. Direct 'smelting', eh? What sort of grade do you suppose you'd need in order to be able to see the silver run?

Lost Geologist said...

A professor emeritus of our uni has a 88-page book about various quick assays on his university website. It includes among others tests for silver.

Silver Fox said...

@Alaska Al, thanks for getting back to me on that question about silver. I guess your answer totally cements your "oldtimer" status, especially on this blog, and you bypassed the web entirely and went directly to a hardcover source (didn't you?).

You'll have to bring your frying pan, we can rent a mule, and I think by summer's end we can have all the remaining silver in the Silver State staked. That is, if either one of us has the time.

@LostGeo I suppose your prof's website is in German?

Silver Fox said...

@Rod, maybe Alaska Al can answer that question about silver grade, I sure can't!

andrew said...

The 88-page guide to "Quick assays in mineral identification" is here and in excellent English.

Silver Fox said...

Funny, that link to the guide only shows up if I go into Post-a-comment mode. So here's the link again - thank you Andrew!

Link is: http://userpage.chemie.fu-berlin.de/~mininst/quickassay.pdf

Lost Geologist said...

That's the guide alright. You found it.

Rod said...

Alaska Al, what do you think? Hundreds of g/t? Thousands?

Andrew, this is a perfect demonstration of why more scientific stuff should be freely available online!

Alaska Al said...

Please, no more Ag questions. I've already shared as much or more as I know.