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chickenminer

Citrine ? Aragonite? Your Opinion ...

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 Okay here is a specimen. I should have given you a size reference in the photos, but the specimen's are about 3" tall.

 When I test it with acid I get a reaction like it is calcite, but only in places. Almost like it has a calcite coating.

 

 

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Chris,

  Aragonite is what I wanted to hear :) .  The fellow that first showed me the source insisted on calling it Citrine but it didn't quite fit.

Some samples I have show the radiating pattern and this stuff is too soft for a quartz.  Got to admit though, the light reaction to HCI

 on the sample I tested was confusing.

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I've seen stuff almost exactly like that - same color, same radiating narrow crystals. Calcite reacts fast with HCL, and so does aragonite, but any additional magnesium or iron slows the reacction way down.(and that piece does have some iron from the color). Often with dolomite (50 - 50 calcium and magnesium), it requires scratching with a needle to turn the material to powder before it will bubble with acid.

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Hi Dick, nice looking specimen. Do you have an untraviolet light?? I have  aragonite that is much lighter but is a nice green under short wave,  Bob

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Oh ... good point Bob. Yes, I have UV short, med and long wave light. I'll have to see what it looks like.

BTW .... that box of rocks I have for you sitting here ( I know, I'm terrible) has a couple nice specimens of this aragonite.

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Dick,

 

I have a Keene acid test kit from WAY back. Citrine is Quartz SiO4 and would not be affected by hydrochloric acid. Aragonite is a carbonate and would definitely react with the expected fizzing. This is just a field test.

 

Is it coated? Coated with what? Is it a mix of something? If so, what? the questions continue...

 

Gemologists use a hand-held gem scope or spectroscope that uses incoming light to make essentially a rainbow of different colors with interference patterns. Gemstones all have identifying finger prints according to the unique spectrum. My wife used one when she was in the gemstone biz. In this case, it doesn't look like any sizeable stones are available for spectroscopic viewing.

 

Thirdly is elemental analysis using an AA spectrometer. It is costly, but an assay lab can do a 30 plus elemental sweep and help define more exactly what you have. This involves destruction of the sample though!

 

- Geowizard

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