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Mystery Gem

Mystery Gem

Mystery Gem

I would like to learn more about this rock that I have come to inherit. It resembles a quartz, and after reading about this mineral I am curious if it is a milky Quartz. Anything you can teach me about this interesting rock would be appreciated! Here is some information to aide in identification.

The gem is opaque, brownish, and clear blue at different areas. It has an earthy/glass like lustre. It seems to have some areas that are layered. It is not easily broken and is pretty heavy for its size.

The origin location is unknown as I inherited it from my sister who received it from someone else.

The steel kitchen knife leaves a scratch on the surface.

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closed as off-topic by user12525, Peter Jansson, Erik, trond hansen, uhoh Sep 4 at 1:19

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Questions about rock identification requests are off-topic. For more information, see the announcement on meta." – Community, Peter Jansson, Erik, trond hansen, uhoh
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  • $\begingroup$ thank you for giving the details,are there any caves in your area where this might have been found. $\endgroup$ – trond hansen Jun 8 '17 at 4:26
  • $\begingroup$ It could be from anywhere. I don't think it is local, but rather from a larger collection. The nearest cave would have been Cave of the Mounds in Wisconsin. $\endgroup$ – Rhizoqueer Jun 8 '17 at 13:59
  • $\begingroup$ I had not considered that. I look forward to hearing more about this! $\endgroup$ – Rhizoqueer Jun 8 '17 at 16:30
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Your mineral specimen is most likely cave aragonite stalactite, based on dendritic shape and physical appearance. A common locality for this type of aragonite is Mexico. aragonite stalactite

Mineral definition for Aragonite. Aragonite is more dense than calcite 2.93 vs 2.71 g/cm3.

Hemimorphite can have a similar appearance but has a significantly higher density. 3.475 g/cm3.

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  • $\begingroup$ maby my deleted comment was on the right track after all. $\endgroup$ – trond hansen Jun 12 '17 at 15:14
  • $\begingroup$ Thank you! would this be considered a speleothem? $\endgroup$ – Rhizoqueer Jun 12 '17 at 15:47
  • $\begingroup$ Yes, I think it would be a speleothem. $\endgroup$ – Gary Kindel Jun 12 '17 at 17:26
  • $\begingroup$ I think that is a possibility but would need to do an acid test to rule out zeolite minerals $\endgroup$ – haresfur Jun 12 '17 at 23:11

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