Jewelry, Gems, & Minerals/Indentification



I feel in love with this on eBayand bought it but the seller didn't know what it is. Can you identify it?

Hi Amy,
This is very pretty but is most likely not natural. You are looking at a chunk of discarded glass from the glass making industry. These are common and are often sold as pretty garden rocks. When the molten glass does not meet specifications it is discarded and left to cool. The white spots in the green glass are caused by impure growth patterns, most likely the unmixing of silica. It could be artificial cristobalite (SiO2) which has the same composition as quartz but a different crystal structure. Cristobalite formation in artificial glass, however, has never really been study. Would be an interesting research.
Nevertheless, it is a beautiful specimen.

Jewelry, Gems, & Minerals

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


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 for details..


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.

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)

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,

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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