# Identify A Rock



## Villano (Mar 18, 2012)

My grandfather used to work in a coal mine in Pennsylvania.  One day, he found this large, football-sized green crystal.  I've looked online at many pictures, but none look just like it.  Are there any amatuer geologists (or, heck, professional ones) out there who can help me identify it?

I'm hoping for "giant emerald" or "kryptonite".


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## Dannyalcatraz (Mar 18, 2012)

Shore is purdy!

Could be a lot of things- including something new or a new form of something old- so IDing it from a photo would be tough.  Things like hardness, refraction and the shape of the crystals would need to be known for a proper ID.

Its color reminds me of some raw aquamarine crystals I've owned in the past, but zircon, flourite, apatite, tourmaline and many other translucent minerals can have that color.  Of those, I believe only zircon is commonly associated with coal, but Mother Nature is tricksy, and likes to change the rules we think we know.  For instance, fluorite is commonly found with feldspar...and feldspar is commonly found in coal.  An uncommon unity could occur, perhaps- I know of all kinds of deposits of minersls that people didn't know existed, and the current world supply Could fit in the volume of a softball.

Then there are minerals like smithsonite which have that kind of color, but don't usually have that kind of translucence.  But again, this could just be an example of something unusually pure.

Considering you're in Virginia, you should be able to find a local mineral club or a college geology department that can figure out what it is pretty easily.


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## jonesy (Mar 18, 2012)

If it was emerald it wouldn't be giant, but you could have it cut into several small ones.


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## Dannyalcatraz (Mar 18, 2012)

Whaddayamean?  There's all kinds of giant- and mostly as yet uncut- emeralds out there.  They're just exceedingly rare.

Gemfields discovers 6,225-carat 'elephant' emerald in Zambia - Telegraph
Giant Emerald Worth Hundreds Of Millions Of Dollars Center Of Dispute In Los Angeles

But they wouldn't look like the OP's stone, for sure.


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## jonesy (Mar 19, 2012)

Oh, well, I meant, like when it's cut, it's like, but how you get it so you can, like use it, and not just, for like, sell. But, brainspill. Dude.


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## Cor Azer (Mar 19, 2012)

Can't help you directly, but [MENTION=183]Acmite[/MENTION] on these boards is a geologist. Not sure if he checks in here regularly anymore. You might find him as Medival Monkey on Circvs Maximvs


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## Dannyalcatraz (Mar 19, 2012)

As I recall, [MENTION=10177]Treebore[/MENTION] is a jeweler and might have some insight as well.


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## Jhaelen (Mar 19, 2012)

It does look a bit like Beryll. How hard is it? Do you have a way to test this?


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## Umbran (Mar 19, 2012)

It is...
It is...

It is green.


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## Dioltach (Mar 19, 2012)

Umbran said:


> It is...
> It is...
> 
> It is green.




"Can it be true, that I hold here in my mortal hand a nugget of purest green?"

Actually, from the wavey, circular pattern I'd say it's some form of volcanic glass. Or perhaps jadeite.


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## Villano (Mar 20, 2012)

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.


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## Dannyalcatraz (Mar 20, 2012)

Has it displayed any brittleness?


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## Villano (Mar 20, 2012)

Dannyalcatraz said:


> 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 ).


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## Dannyalcatraz (Mar 20, 2012)

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.)


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## Villano (Mar 20, 2012)

Dannyalcatraz said:


> 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.


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## Dannyalcatraz (Mar 20, 2012)

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".


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## Aeolius (Mar 20, 2012)

Green Obsidian ?


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## Nellisir (Mar 20, 2012)

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.


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## Treebore (Mar 20, 2012)

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.


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## Treebore (Mar 20, 2012)

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.


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## Thunderfoot (Mar 20, 2012)

[MENTION=10177]Treebore[/MENTION] [MENTION=505]Villano[/MENTION]

We have oxidized copper in limestone and quartz that looks a lot like that around here.  Those old limestone deposits hold all sorts of minerals, gold, silver, copper, iron, etc but nothing worth trying to mine (either too little or too impure) but with the exception of the gold, most of it ends up oxidizing and altering the color of the clear quartz encasing it, at least until the quartz is lopped off.

Might that be what you have here?  Hope this helps.


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## Dannyalcatraz (Mar 20, 2012)

I was thinking aqua erly on, based on color, but as pointed out, the crystalline structure is off.

I REALLY don't think it's obsidian- as i understand, it should have flaked with the application of the knife.

The agate idea seems good...I was also thinking some kind of blue-green chalcedony.


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## TarionzCousin (Mar 21, 2012)

Let me assist you by narrowing down the possibilities. It's not a ruby.


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## Dannyalcatraz (Mar 21, 2012)

Very helpful, as always!


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## TarionzCousin (Mar 21, 2012)

Dannyalcatraz said:


> Very helpful, as always!


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## Villano (Mar 22, 2012)

Treebore said:


> 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.




What areas do you need to see?  I take a close of picture of them if you think it would help.




Nellisir said:


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




There is a college nearby and I found the e-mail of the Earth Science professor, so I think I'm going to send him a message.


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## Treebore (Mar 22, 2012)

A lot of that looks like it was just "poured", but there seem to be some areas that look squared off or blocky, those may actually be true "structure", so if you could get close ups they may give me solid clues.


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## Treebore (Mar 22, 2012)

Also do you possibly have a piece of good broken glass? Sharp? If so see if it will scratch it.

Also, if you truly did scratch it, not just draw a thin line, with that knife, I already know it isn't beryl.

Also see if you can find a copper, COPPER, penny, and a true IRON nail, and try scratching with them.

Make sure it scratched the stone, and that your cutting object is not just leaving a residue. So rub it after wards, see if you wipe it off, or feel an actual scratch etched into it.


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## Treebore (Mar 22, 2012)

If you can get your hands on HCL (be very careful with it if you can, serious chemical burns will result!) (aka Hydro Chloric Acid) put a drop  or two on flat(ish) areas of the stone and let me know if it bubbles.


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## Treebore (Mar 22, 2012)

Another possible clue you can give me, do you know the conditions of the mine in which it was found? Like was there a good amount of water present? Was the mine described as being in solid rock? That kind of info.


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## Treebore (Mar 22, 2012)

If you did actually scratch it with that knife I am currently leaning towards Celestine. It is only a 3.5 hardness, so doing those hardness tests, confirming there is actual etching occurring, or not, can totally change the possibilities.

If you can get HCL that will help eliminate the Calcium minerals. Or confirm it.


Also, testing with the glass is the most telling of everything at this point, so make that your highest priority.

Another possibility is Zircon. But anyways, these are all still mostly guesses at this point.


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## Treebore (Mar 22, 2012)

Couple of more ideas. 

Do you own a "black light"? If so see if it fluoresces under it.

If it does, and feels "oily", AND if the glass does NOT cut/etch it, ummm... stay away from it. At this point you may have a radioactive zircon. Not super radioactive, because if it is Zircon, it is this color because it is already past its "half life".

Know anyone with a radiation measuring device? Ask them to check for Gamma.

Now the cool thing, if this IS Zircon, you would own among the oldest rocks that make up this planet. Plus the glass clean stuff is used as gem stones.

Still, don't sleep with it, or keep it near you until we can tell more.

Edit: OK, I checked the radiation info, and IF this is Zircon your only supposed to have to worry about radiation when they are the super deep blue colors. So you should be safe IF it ends up being Zircon.


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## El Mahdi (Mar 22, 2012)

It's fossilized Dwarf poo...


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## Dannyalcatraz (Mar 22, 2012)

Nope- that would be anthracite.


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## TarionzCousin (Mar 23, 2012)

It's not a diamond.


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## Dannyalcatraz (Mar 23, 2012)

That would be fossilized _constipated_ Dwarf poo.


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## Grumpy RPG Reviews (Mar 23, 2012)

It is kryptonite and the rock which gave Caine Marko his powers way back when.


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## Villano (Mar 23, 2012)

Treebore said:


> Another possible clue you can give me, do you know the conditions of the mine in which it was found? Like was there a good amount of water present? Was the mine described as being in solid rock? That kind of info.




I have no idea about the mine.  My grandfather had the rock since before I was born and he passed away in the early 90s.




Treebore said:


> If you can get your hands on HCL (be very careful with it if you can, serious chemical burns will result!) (aka Hydro Chloric Acid) put a drop  or two on flat(ish) areas of the stone and let me know if it bubbles.




No offense, but I don't want to mess around with any acid.





Treebore said:


> Couple of more ideas.
> 
> Do you own a "black light"? If so see if it fluoresces under it.
> 
> ...




No, I don't own a black light or a geiger counter, so I...wait, radioactive?  Oh, my God, I'm gonna die!  I'm gonna die! 



Treebore said:


> Edit: OK, I checked the radiation info, and IF this is Zircon your only supposed to have to worry about radiation when they are the super deep blue colors. So you should be safe IF it ends up being Zircon.




Oh, well, never mind then. 

Anyway, I don't have any sharp glass, but I checked with the exacto again.  It's cutting into the white, but, like I said, I'm not sure it's scratching the green.  I'm including a few more pix, but I'm wondering if the white and green are two different things.  It looks like the white is suspended within the green.


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## Dannyalcatraz (Mar 23, 2012)

What you're seeing within the green could be fracture planes, inclusions of another mineral, or just a less pure version of whatever it is.  I'm leaning towards the first 2.


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## El Mahdi (Mar 23, 2012)

Villano said:


> No offense, but I don't want to mess around with any acid.




Lemon or Lime juice (concentrate), or vinegar might work.  I believe they work with limestone.


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## Dannyalcatraz (Mar 24, 2012)

FWIW, here's a *biiiiig* emerald:

World famous jewels | Photo Gallery - Yahoo! News


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## Jhaelen (Mar 26, 2012)

Villano said:


> I'm including a few more pix, but I'm wondering if the white and green are two different things.



Actually I thought it's likely that it's different minerals. Even with the new pictures the green looks mostly amorph. I cannot tell if it has any crystalline structure. Maybe it's obsidian after all?

Googling some images showed up an example with a very similar colouring:
http://images.bidorbuy.co.za/user_images/906/394906_091111161341_obs5.jpg


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## Dannyalcatraz (Mar 26, 2012)

It could be, but he said the knife wasn't really doing much to the green, translucent parts.  Obsidian would flake or some such, I believe.


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## Thunderfoot (Mar 29, 2012)

Limestone, oxidized copper and quartz...  I'm sticking to my guns.


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## Dannyalcatraz (Mar 29, 2012)

> I'm sticking to my guns.




You clearly need a better gun lube.  Or should stop rolling in honey before strapping up.


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## Theo R Cwithin (Mar 30, 2012)

Dannyalcatraz said:


> You clearly need a better gun lube.  Or should stop rolling in honey before strapping up.



A Deadlands game with you would be disturbing, I fear.


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## Dannyalcatraz (Mar 30, 2012)

A Deadlands game with me would be hilarious, awesome, fun...AND disturbing.  I will have a character named Purity Balls, the twin .45 slingin', cigar-smokin', hard-drinkin', wild-seed daughter of the Rev. Ezekiel Leviathan Balls.


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## Villano (Apr 5, 2012)

I sent an e-mail to the Earth Science professor at the local university, so we'll see what he has to say.

Also, I tried the vinegar test and nothing bubbled.  And I'm not sure if I mentioned it, but the mine was an anthracite coal mine (not sure if that helps).


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## TarionzCousin (Apr 7, 2012)

Villano said:


> Also, I tried the vinegar test and nothing bubbled.  And I'm not sure if I mentioned it, but the mine was an anthracite coal mine (not sure if that helps).



Oh, that helps. It's not coal.


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## Dannyalcatraz (May 7, 2012)

I went to the InterGem show at Dallas Market Hall last weekend, and my friends at Mineral Search (Little Elm, TX) had a mineral specimen that strongly resembled what you have.  Theirs was aquamarine.

Any news on yours?


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