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What is this rock?

0 votes

This rock is heavy and was found in southwest Washington. The outside as you can see is malachite green and the interior (and I hope you can see it) looks like agate material, dark grey mostly but clear, like smokey quartz. It is quite beautiful. Found a whole seam of this material in an abandoned rock quarry.

asked Sep 4, 2017 by trishberrong (250 points)

1 Answer

+1 vote
http://www.minerals.net/mineral/chrysocolla.aspx

Here is a link to chrysocolla. Google it and check the images. You may be able to find one which is similar. Take the sample to a rock shop and they can confirm it. I think malachite and chrysocolla are the best guesses right now.
answered Sep 12, 2017 by Weasel (42,940 points)
Thanks Weasel, I did some research and perhaps chrysocolla and chalcedony. Saw several pics that had the green/blue crust with the grayish stone.
May also be malachite or some other copper-bearing mineral. Any way to provide additional info such as streak or effervescence in acid?
I will do a streak plate test. What kind of acid? Can't get hydrocholoric.
Muriatic acid, which is hydrochloric acid, can be purchased in stores like home depot in the masonry section. If you can't get that, another strong acid, which is easily available, is "Lime Out."
 


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