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1,634 questions

2,886 answers

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5,087 users

Onyx or chert

0 votes

Help me identify this piece which is polished by me. It was broken from a geode like rock in the Himalayas ( Asia)alt text

asked Nov 1, 2014 by Hunter (740 points)

10 Answers

0 votes

Looks like an agate which is a chalcedony of sorts.

answered Nov 1, 2014 by Weasel (31,710 points)
banded agate for sure, chalcedony is generally not banded
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Could also be travertine. Hardness and effervescence can both easily determine if it is one or the other.

answered Nov 5, 2014 by hershel (44,400 points)
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It could be a salt.

answered Nov 5, 2014 by Weasel (31,710 points)
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But I think rock like quartz

answered Nov 5, 2014 by Weasel (31,710 points)
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Definitely not salt and more likely travertine over quartz due to patterns and luster. As mentioned though a definitive way to test would be with effervescence in acid or hardness...

answered Nov 7, 2014 by hershel (44,400 points)
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He said he found inside a geode does that change your opinion any, Herschel?

answered Nov 7, 2014 by Weasel (31,710 points)
0 votes

A geode would indeed indicate a more typical quartz/agate combination, but although he mentions geode, the description is vague. Hunter - can you please provide more info on its "geode-like" habit, as well as some more pictures? Thanks.

answered Nov 9, 2014 by hershel (44,400 points)
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The geode was broken open. Inside the geode i found sandstone like rocks. The above sample is that of the geode itself.alt text

answered Nov 9, 2014 by Hunter (740 points)
0 votes

alt text

answered Nov 9, 2014 by Hunter (740 points)
0 votes

Thanks for your additional photos. Are your pieces cut and polished?

Now the easiest way to determine the true nature is by effervesence. Can you place some even (even a weak acid such as vinegar) and place it on a surface (i.e. best way to do this is with a liquid medicine dropper) and see if it forms small foaming bubbles?

answered Nov 10, 2014 by hershel (44,400 points)
 


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