Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
Morning Ken. I presume you are referring to impact glass, like moldavite. Most of this material is imitation, man-made glass. Is there a market for it? Yes, Usually New Age types.
Joined: Wed Jan 23, 2013 5:29 pm Posts: 1047 Location: Paris
Libyan glass is nice looking too. I once saw necklaces made of alternating beads of moldavite and libyan glass, the color association was pretty and the general idea interesting.
In another style, you have the brazilian carbonado diamond.
I've researched this subject for almost 3 years and you are right. All I could find is peridot or moldavite, which is referred to as impactite gemstones. The reason I've been researching it is because my family has a collection of stones and gemstones that appear to have been altered, modified, morphed or created during a major meteorite impact event in the distant past. We tried to get an appraisal on a couple of them and as was told that a dollar amount could not be assign to the stones because there was nothing to compare them to. There are stones that appear to be some form of altered, modified or morphed serpentine, jade or jasper.
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
Sidebar: The peridot found in pallasites is not the result of impact.
RE: Your family's collection. What characteristics are you basing this hypothesis on?
It seems far more likely that the examples you describe have undergone alteration due to terrestrial, not extra-terrestrial events. Perhaps you could upload a couple of pictures of this material and we will try to shed some light on your anomalies with processes we can explain using known petrological and/or mineralogical processes.
The first step in an appraisal would be a proper identification of the material in question. If your appraiser didn't start there I would question all subsequent statements from that source.
Serpentine, jade or jasper are common and well understood stones. What was the qualification of the source of information
Here's a photo of one of the stones. Told it could be some form of altered jade maybe chalcedony? Can only show 5 photos at a time so I hope this shows enough to give some ideal.
That conchoidal fracture in the last picture is suggestive of chalcedony. Overall look is of moss agate. A nice find, but not jade. Nothing about it suggests a meteorite impact. Nevertheless this looks to be nice material that would be worth having cut into cabochons.
For me to sit here and convince someone that this is meteoritic material, I'd have to waste your time with a lot of geology and several electronic scan results. It took me almost five years of research and several scans to get to that point. Regardless of what it is or isn't, it's for sure something cool to look at. This little stone below has me really baffled, a Raman analysis says it's quartz but it can't be scratched with a 7 or 8 from a mohs hardness test set, if you press hard with a #9 it will scratch it.
Of course all we are basing our opinions on are pictures provided by you. But as Barbara has said, we have invested much time in education and experience to form a knowledge base. I think we have been very open in our limits under the circumstances of not having the opportunity to examine the samples in our labs.
As for the new stone,
As far as I know, a properly done Raman Spectrograph is definitive. The Raman for Quartz is so constant, simple, and distinct that it is used to calibrate Raman Spectrometers. I would be very surprised to see a Raman miss a Quartz identification.
Are you questioning it just based on a scratch test?
What set of hard points are you using for this test?
Why not polish flat on it and get an RI?
Get as SG?
Examine under a polariscope.
Quartz is a pretty easy identification to verify....
Last edited by 1bwana1 on Thu Apr 25, 2019 6:06 pm, edited 1 time in total.
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