Help! Is this GREEN OBSIDIAN?

[Boneyard]

This is a 10" long, 6" Tall, 6" wide chunk of something? I was unable to weight it, heavy, approx. 20-25 lbs. no bubbles? Thank You

 

[Boneyard]

Given that it was in a collection from a California geologist, I lean toward it being a rock.
One of my first thoughts was a nice piece of chrysoprase, green chalcedoney, which is found in California.
It does also look like slag glass. A hardness test will tell the diference.

What is a hardness test and how do you go about conducting one?

 

[Turkısh Man]

http://www.mineraltown.com/articles/egypt/vetro.jpg


Desert Silica Glass

In a remote area close to the Libyan border, there are bits and pebbles of natural glass. They currently seem to be related to tectites, but their nature is still debated. They were used to make tools during pre-Historic times and in Faraonic times in jewelry

http://www.treasurenet.com/forums/rocks-gems/111047-green-obsidian.html


http://images.google.com/search?hl=...0&bih=791&sei=XXuSUJ2RD5KKhQfK-oCIAg&tbm=isch

 

[Bajahunter]

Google Mohs hardness scale.
Basically you use one type of rock to try to scratch another. If the other rocks is scratched then it is softer.
Quartz and chalcedony (both silicon dioxide) have a hardness of 7-7.5, while glass has a hardness of 6 to 6.5. So if it is glass you should be able to scratch it with a known piece of quartz. If it doesn't scratch then it is chrysoprase.
Moldivite is glass so it should be scratched by quartz. Fluorite is a hardness of 4. Also fluorite wouldn't have as clean of a concoidal fracture as your piece exhibits.

 

[StoneWhisper]

Hell we all keep stuff we're not sure about.. So if soemone like what they see or collect, let them.. I eman I have a few items which I can't trash, but keep them never the less..As posted in the pic via earlier post.

 

[Boneyard]

Thank You Bajahunter, I appreciate your help and time

 

[StoneWhisper]

Just to throw a monkey wrench into the works.. I've even seen Aquamarine look very simular as tot he images above.. But my belif that the stone/glass is simply that is because of the sharp points.. thou it very well could have been confusded with obscindain.. because of its light (see through) appearnce just tells me its nothing more then glass.

 

[rock]

Well if you do the test on it let us know the results.

 

[unclemac]

no no no.....the glass doesn't come from outer space...it is created by the impact of a large extraterrestrial object that hits the earth. The
Egyptian glass you speak of is called "Libyan dessert glass" and yes, the Pharaohs did us it...this was King Tut's..

the yellow stone in the center is dessert glass.

I have some ancient Libyan glass tools and would say that if your pictures are true to color...then your specimen is not this.

https://www.google.com/search?hl=en...511441ea7da2f1&bpcl=37189454&biw=1280&bih=557

take a look at these.....

 

[Eu_citzen]

I think there is a find of green obsidian in Calif. (Burns Green Obsidian?)
However it is easy to confuse with slag glass for sure.

Why not ask one of the colleges if you can find them? They might know something more.