Monday, March 17, 2008

St. Patrick's Day Green

Above: A copper-bearing rock with Malachite, Azurite, and Chrysocolla.

Above and below: Malachite, credit to The Lost Geologist.

Following on from Ron's Green Guessing Game (GGG) at, I'm posting these photos via email. Feel free to name the main mineral, or any others you see. I hope these will turn out, as I have only tested email posting once.

Well, the email thing didn't quite work, so here they are, late on St. Pat's Day. Oh, and the orange is for my dad.

Update: Tuff Cookie has some green rocks and an explanation about what they are.

And: Andrew has another green rock, a bit of a mystery.

More green rocks/minerals: Julian has a green mystery mineral, The Lost Geologist finally found a green mineral, and Brian has a green outcrop!


Garry Hayes said...

Did you toss us a bit of mariposite there?

Silver Fox said...

Well, no. Ron has some fuchsite, though. You'll have to look again!

Mathias said...

The upper to pieces look like part of an alteration zone or weathering of some kind. I like easy answers so I would propose Malachite.

Silver Fox said...

That's an easily correct answer! Malachite it is. There are a couple other minor minerals (besides the mostly leached capping of a copper deposit with silica and Fe-oxide, no doubt) - but the other minerals aren't really green, one is blue, and another is blue-green - but they are harder to see.


Mathias said...

Thanks! Malachite was the only green mineral I could think off in connection with alteration or weathering (or leaching). :-)

Any idea what the blue stuff on those samples it? It's too small to recognise on the fotos.

Silver Fox said...

The bit of blue in the upper left corner is azurite, another copper carbonate. The other blusih-green massive looking stuff (or microcrystalline), which colors most of the rock, is probably chrysocolla. It's usually turquoise-colored.