Tanzanite
Tanzanite is a relative newcomer as far as gems go. Discovered in 1967 in the African nation of Tanzania, the initial pocket of mate- rial was quite small. Many stories are tied to its discovery…
Featured ArticlesBlue Topaz Update
Acting on a complaint earlier this summer, the NRC informed retail jewelers that they may be selling blue topaz in noncompliance with NRC regulations. The NRC letter also purportedly requested the names of the retailers…
Featured ArticlesElemental-Focus on the Spectroscope
Among these, the spectroscope is generally the most difficult to initially master. This fear factor leads students into a self-fulfilling cul-de-sac where lack of skill leads to lack of success and the eventual conclusion that…
Featured ArticlesEmeralds: New Green Pastures and Possible Trouble in Paradise
While so many good things have happened to emeralds in this decade, dealers in Colombia are in danger of giving it all away. It took years to regain confidence in emerald treat- ments following the…
Featured ArticlesTreated or Enhanced- Is There a Difference?
Our industry is known for its liberal rules when it comes to the English language. Actually, we tend to make our own rules to fit the need at the time if the English language does…
Featured ArticlesColor Communication and Quality Grading of Colored Gemstones: A Non-Technical Look at the Technology Behind Grading
Pigeon blood ruby. Cornflower blue sapphire. Flame red spinel. The names conjure up great images in the mind of what these gems look like, but do we really know what their color is? Are these…
Featured ArticlesCuprian Tourmaline
Cuprian tourmaline is the variety of copper bearing tourmaline mined from locations other than the original source of copper bearing tourmaline in Paraiba, Brazil. The GemGuide considers Paraiba to be an origin-specific trade name…
Featured ArticlesAndesine Feldspar
Transparent red andesine appeared in the market in 2002. At first, only small quantities were observed. Dealers stated that the apparently new, rare, stone was coming from a small deposit in the Congo. The GMN…
Featured ArticlesOrigin- Where is it Really From?
Only two people know the origin of a gem: God and the miner and the second is suspect. C.R. Beesley, American Gemological Laboratories, 1982. The father of origin determination is considered to be the late Dr…
Featured ArticlesGem Rough Scams
This seems logical enough since most finished rubies and sapphires are less than one carat in size. But that little fact does not stop the ethically challenged from singing the praises of gem quality corundum…
Featured Articles