I love spinel. The GIA reserach compares two purple gem spinel samples with regard to trace element chemistry and visible light absorption spectra, and presents the first reported example of a spinel with a saturated purple color caused predominantly by chromium and cobalt. The GIA research findings are a must read for gemologists, colored gemstone traders, jewelers, collectors, and consumers.
Insightful field report. Must read. Despite the Neyshabur mine's productivity and tradition, this turquoise has yet to find its place in the global market. Although most turquoise in the global market is either stabilized or treated, Iranian traders insist on focusing on untreated turquoise. While the untreated version of the gemstone may be important to some customers, its high price, limited quantity, and sensitivity to chemicals are a drawback for others.
A useful reference for the gemological community. Many thanks to the pearl researchers at GIA.
Untreated colored stones are becoming very rare these days.
A useful reference for gemologists, pearl dealers, and consumers.
The GIA research report on the effects of fluorescence on diamond's appearance is a must read for gemologists, jewelers, diamond dealers and consumers. Fluorescence is a unique property of diamond that can improve the color of some stones when they are exposed to a lighting environment with significant UV content, such as daylight, but fluorescence alone does not noticeably reduce transparency. At the end of the day diamonds are for personal adornment and consumers are the deciders.
Consumers beware. If doubtful, always consult a reputed gem testing laboratory like the GIA.
Gemologists, gem dealers, consumers beware. Today microscope is not enough. You need LA-ICP-MS and Raman spectroscopy to assist positive gem identification. Many gem testing labs can't afford expensive analytical gem testing instruments. Ask questions if you are doubtful.
Nature has no rules. Take a look at the stunningly beautiful but bent rutile inclusion. Many thanks to Amy Cooper and Nathan Renfro of GIA.
Take a look at the unusual fluorescence of a color-enhanced amber bracelet.
The majority of fine-quality Shi Zi Hong agate, one of the most famous color varieties of Nanhong agate comes from Liangshan Yi Autonomous Prefecture in Sichuan Province, China. The price is higher for the highly saturated orange red color variety with a fine texture. Since it is a popular colored stone in China, consumers in the market looking for Shi Zi Hong agate must expect plenty of treated and imitations varieties.
The unusual aventurescent effect was caused by the scattering of light from small pyrite inclusions not typically seen in common opal. Nature has no rules.
It is unclear why anyone would go to the trouble to treat a synthetic ruby with lead-glass filling, consumers and gemologists should be aware that such material does exist in the gem market.
Chatoyancy or cat's eye effect are quite rare in opal. Here is a pleasant surprise.
Nature has no rules. Finding two examples of bicolor diamond crystals that show distinct pink and colorless sections is an extraordinary find.
Without inclusions there is no asterism effect. A clever design choice may have produced two cabochons displaying asterism. Truly rare.
