# What type of rock is this that is light colored with greenish crystals?

I found this rock. It is probably a very common rock but could an expert please tell me what rock this is?

• I would upload it and categorize it as: commons.wikimedia.org/wiki/… – tobias47n9e Apr 17 '14 at 11:02
• you should add the tag geology before the current :-P but seriously, this look like olivine to me. – hugovdberg Apr 17 '14 at 11:05
• This question appears to be off-topic because it is too localised, and unlikely to be of use for any future visitor of this site. – gerrit Apr 17 '14 at 14:20
• It would really help to know where this came from, and some basics like density, hardness, etc. A better-lit photo might help too. – kwinkunks Oct 5 '14 at 1:21
• Please see this link to improve the probability of properly identifying this specimen: meta.earthscience.stackexchange.com/questions/124/… – Inkenbrandt Mar 3 '16 at 22:31

How about a [dioptase]? 1 Dioptase is an intense emerald-green to bluish-green copper cyclosilicate mineral. It is transparent to translucent. Its luster is vitreous to sub-adamantine. Its formula is $\ce{CuSiO3·H2O}$ (also reported as $\ce{CuSiO2(OH)2}$). It has a hardness of 5, the same as tooth enamel. Its specific gravity is 3.28–3.35, and it has two perfect and one very good cleavage directions. Additionally, dioptase is very fragile and specimens must be handled with great care. It is a trigonal mineral, forming 6-sided crystals that are terminated by rhombohedra.

• +1 for your answer, but I would also like some more opinions to make sure. – Kenshin Apr 17 '14 at 9:04
• Maybe it is green Fluorite? – tobias47n9e Apr 17 '14 at 16:15
• Dioptase is not a common mineral, and not really this colour so I'd say this answer is likely incorrect. – kwinkunks Oct 5 '14 at 1:20
• It is definitely not Dioptase. Dioptase is a much darker shade of greenish blue. – Gary Kindel Dec 27 '14 at 3:48
• @L.B. I suppose that depends on the locality in which it was collected. I have identified fluorite with grainy, sometimes even crumbling physical structures. – person27 Jul 20 '15 at 2:08

It is more likey to be fuchsite (chromiferous muscovite mica)

Google Image Search: Green muscovite mica

• Fuchsite is fairly uncommon to find lying around without actively searching. It's probably something more common, I would think. – person27 Jul 20 '15 at 2:03
• I was thinking this but the green doesn't really appear to be a mica. Hard to tell from the photo. Perhaps diopside. maurice.strahlen.org/minerals/diopside.htm – haresfur Mar 4 '16 at 2:46

Chlorite schist (rock) epidote or prehnite (mineral) all common to upper Great Lakes region

• There is no indication that it is from the upper Great Lakes region in the question. Also, you haven't given any explanation as to how you arrived at this conclusion. From my experience it doesn't really look like a schist. – bon Mar 4 '16 at 13:35

My thought is diopside, which can have a similar colour and be found with a white (plagioclase?) matrix.

• Note: diopside and dioptase are different minerals. – haresfur Mar 6 '16 at 22:34

Its such a bad picture but it could be olivine or paradote.i highly doubt it to be chrome diopside which is rare and valuable as a gemstone