• Register

Information for users from the old Q&A site
If you have an account from our old Q&A site, your account was transferred over, but you need to reset your password and confirm your email address.
Reset Password here
Confirm Email here

2,207 questions

3,853 answers


47,473 users

Dark glassy mineral

0 votes

Hello. Found this stone in the sands for construction. 
Its heavy and glassy opaque and when i shine a flashlight into it shows dark-brown red-brown color

Would you please help me to identify this mineral

asked Aug 19, 2017 by Amirsardari (180 points)

3 Answers

+1 vote
Obsidian looks like this. I would say obsidian. You have volcanic glass. The conchoidal fractures in the first picture confirm it for me. Ancient peoples chipped flint and obsidian into these very hard stones to make tools with sharp edges.
answered Aug 19, 2017 by Weasel (57,990 points)
Thank you very much. I live in belarus. Here there are no mountains nor volcano. Interesting for me how this mineral is formed in this condition
+1 vote
Ice age glaciers move tons of matter around. I do not insist I am correct. So do floods and rivers. Take it to a rock and mineral shop, a university or a lapidary. It could certainly be something else. Where I live, there are no volcanoes and the mountains are hundreds of miles away, but I found agate and puddingstone dragged here by glaciers.
answered Aug 19, 2017 by Weasel (57,990 points)
0 votes

If its not from a volcanic zone, the color and fracture would indicate flint or chert.

answered Oct 27, 2017 by hershel (51,840 points)