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Hi guys,

On a recent trip I found a strange looking mineral specimen. It was in an area covered by a large iron gossan and several veins of ironstained quartz showing signs of copper enrichment. The specimen is very heavy and glassy. Hardness is above 7 but I was able to scratch it with a carbide bit...so maybe 7-8. Streak test was inconclusive. It either left a whitish streak or it ground off the porcelain. Any help with an ID would be great!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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16 minutes ago, ArcticDave said:

It is very glassy. Slightly greasy feeling as well.

Except for the color is does look like glassy massive quartz at first glance.

:idunno:

 

 

The glassy greasey/oily look is why I was thinking Jade.

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18 hours ago, Morlock said:

Could it be a surface coating of aventurine?

What I see doesn't jive with aventurine. Second picture seems to show some fairly well defined crystals. I think it's massive quartz with colorization from a secondary mineral. Really hard to say though without specimen in hand or more information.

Edited by d_day
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It does appear to be a colored quartz of sorts. There are growth rings inside if you look closely. I was unsure as I've never found quartz of this color in this part of Arizona...and I've looked at hundreds of veins in the area. I'm positive the coloring has something to do with the copper deposit considering it proximity to a good sized lode. I was hoping someone knew what colored it.

Thanks guys.

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To me it looks just like the picture of aventurine in the Smithsonian Rock and Gem guide.  The other type of quartz in the guide that has green copper coloring is chrysoprase, but to me chrysoprase looks like green turquoise.  I did not know that Jade was found in AZ, but I guess it is.

Regardless of what it is, I'm starting to get interested in lapidary and wonder what a slice would look like.

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Nephrite jade has a Mohs hardness of 6.  Jadeite jade is between 6.5 and 7.  A decent stainless steel knife blade has a hardness around 6.5.  Maybe try scratching your chunk with such a blade to see what happens.

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 None of my knives will touch it, but all mine are carbon steel. I don't have any SS blades. A small triangular file I have was able to file a nice notch across an edge. I am finding conflicting info on translating rockwell hardness to mohs, so I'm not sure the mohs hardness of the file.

Chrisski...

I'm thinking of doing just that. I remember Bill saying he had a rock saw. I'll see if I can cut a slab and polish it.

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Look-up the geology of the area where the sample was found.   Usually there will be a listing of the minerals found in that area.

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