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Jewelry, Gems, & Minerals/Turquoise identification

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Question
1st ring with spiderweb turquoise stone
1st ring with spiderwe  

2nd ring with blue, white and grey stone
2nd ring with blue, wh  
Hi, I have two sterling rings (both vintage 1970s Native American made pieces) with stones in them that have me stumped as to the types of turquoise they are, (or, in the case of one, whether it is even turquoise), am hoping you can help me with this.

The first has lovely red and gold spiderwebbing in a stone that ranges from blue to green with a tiny bit of white as well. I'd thought maybe Red Mountain turquoise or even Blue Gem turquoise, based on the color of the stone, but I haven't seen a lot of Blue Gem with spiderwebbing.

The second is a real stumper, as it has blue, white and grey in the stone, but not in the usually seen turquoise proportions.  I'd thought maybe the second stone might be a type of agate, or even jasper, but I can't find any stones online that look quite like this one.  If it is turquoise, I'm wondering what type it could possibly be.

Hoping you can help me ID these 2 unique and very lovely stones.

Thanks and best wishes,

Sue

Answer
Sorry that it took me so long to get to your question. I was out in the field leading a geologic excursion.

Now to your question: Identifying stones from pictures and descriptions is notoriously difficult, but I will give it a try.

If you are certain these are vintage pieces then they are most likely real. Fake turquoise did not appear until the 1980s. So you 1970 specimens are most likely the real thing.

As far as your second stone is concerned, there is indeed white turquoise. It usually is mixed with the blue variety and as it looks like in your specimen with some of the grey matrix host rock as well.

Now, chemically, all turquoise is a hydrous phosphate of copper and aluminum (CuAl6(PO4)4(OH)85H2O). If Copper can be detected within your stone then you would have an indication that your turquoise is real. This test can be done non-destructively with an X-Ray Fluorescent Spectrometer or XRF for short.

If you are in the Denver area we could do such a test for you. It is a very rapid test and you could certainly watch while we do it. Maybe your local university geology department has such an instrument and will run the test for you.

Sorry that I can not be more helpful but maybe this little bit of info helps.

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Uwe Richard Kackstaetter, Ph.D. (Dr.K)

Expertise

I can answer questions concerning minerals, mineralogy, gems, metals, and anything that has to do with geology. However, I am NOT a jeweler. Questions about values, settings, gem stone cuts and appraisals are best directed to other experts on this site. I can however aide in the identification of unknown mineral materials. As a public service and part as training for new geoscientists, our university department provides FREE mineral identification for individuals. Please contact me for details or go to http://college.earthscienceeducation.net/MIN/MINID.pdf for details..

Experience

I am a professor of applied geology and mineralogy with many hours of field experience. Furthermore, I enjoy recreational gold prospecting and mineral collecting. As a professor I am engaged in research concerning minerals and their occurrence.

Organizations
Member of the GPAA (Gold Prospectors Association of America) as well as the Association of Environmental Geochemists. Member of the GSA (Geologic Society of America) Member of the AIPG (American Institute of Professional Geologists)

Publications
Here is a small sampling: Mineral-rock handbook: Rapid-easy mineral-rock determination : written for anyone interested in minerals and rocks - Proctor, Peterson, and Kackstaetter;Macmillan Pub. Co. (New York and Toronto and New York) Physical Geology Laboratory e-Manual [CD-ROM], Kackstaetter, Earth Science Education LLC Colorado Front Range Self-guided Geology Field Trips, Kackstaetter, http://www.scribd.com/doc/27175290/Colorado-Front-Range-Self-Guided-Geology-Field-Trips

Education/Credentials
Ph.D. in Applied Geology and Mineralogy. I am actively teaching courses in mineralogy and a variety of field courses with mineral collecting opportunities. Background in precious metal exploration.

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Numerous!

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