Identify A Rock

[Villano]

Thanks for the replies. There are a few suggestions I hadn't considered before. Unfortunately, my rock kind of resembles all them in some ways and none of them in others.

When I posted this pic, I was hoping someone would say, "Oh, that's clearly a so-and-so" and wrap up the mystery in one reply.

I looked up how to do a hardness test. You can't scratch it with a fingernail or penny. I ran an exacto knife across it and it does leave a scratch on the rough, white areas, but I can't see if it's making a mark on the green crystal areas (it's sort of transparent, so it's hard to see).

I'll PM Acmite and Treebore and see if they can help.

 

[Dannyalcatraz]

Has it displayed any brittleness?

 

[Villano]

Has it displayed any brittleness?

Nope. It's very hard and heavy. The white areas feel like rough stone and the green feel like...rock candy or plastic.

It's very solid and heavier than it looks. If I dropped it on my foot, I would break it (my foot, not the rock ).

 

[Dannyalcatraz]

What I mean is, when handled, is there any flaking? When you applied the knife, did anything break off?

(Right now, I'm leaning towards some kind of topaz.)

 

[Villano]

What I mean is, when handled, is there any flaking? When you applied the knife, did anything break off?

(Right now, I'm leaning towards some kind of topaz.)

No flaking. It's all very solid. Running the knife across it just puts a light scratch on it. I'd ruin my knife before damaging the rock.

 

[Dannyalcatraz]

Maybe not topaz, then, and definitely not a volcanic glass.

I'm puzzled, since most of the things I'm thinking of are hard but "brittle".

 

[Aeolius]

Green Obsidian ?

 

[Nellisir]

Do you have a local college you can take it to?

Based on my total lack of expertise, it looks like green quartz to me.

 

[Treebore]

If it had a definite crystalline it would be much easier to say. Since you say it is very heavy for its size and is scratched by steel it is definitely not Topaz or harder. Based on the picture I seriously doubt it is Beryl (Emerald), but a couple of small areas make it possible. I have also seen quartz formed like that. Simply put, its impossible to say with just a picture since it has no definable crystalline structure. A couple of small areas look like they may have such structure, so if you can take a close up pictures of those areas, maybe.

It may also be some type of Agate. Certain sections of it remind me of that as well.

 

[Treebore]

Plus if that is Beryl the color is wrong for Emerald, it would be in the sea green Aquamarine color range. Which is actually more desired by older collectors, because that used to be the desired color for Aquamarine. Sky blue colors have only been more popular since the 60's.

Just like real collectors, in my opinion, want to see silk in their rubies, which is the only way for them to have that old "mythic" glow.