GIA Names New Mineral Crowningshieldite

Diamond Education

Picture of GIA Names New Mineral Crowningshieldite

The Gemological Institute of America (GIA) has discovered a new mineral while studying flaws in large diamonds from the Letšeng mine.

The organization named the substance crowningshieldite after G. Robert Crowningshield. The 50-year GIA veteran and pioneer of gemological research wrote the first report on gem-quality laboratory-grown diamonds in 1971, the GIA said Tuesday.

Crowningshieldite is a nickel sulfide mineral with a hexagonal crystal structure, and forms when diamond inclusions undergo chemical modifications. GIA research scientist Evan Smith and his team, together with researchers at the University of Padova, identified the compound in two stones from Gem Diamonds’ mine in Lesotho, which is known for producing sizeable diamonds. They came across the mineral while examining inclusions in CLIPPIR (Cullinan-like, large, inclusion-poor, pure, irregular and resorbed) diamonds, a variety of large, high-quality, type IIa stones that form at significantly greater depths than most diamonds do.

“Discoveries such as this propel our understanding of diamonds and the earth forward,” said Tom Moses, the GIA’s executive vice president and chief laboratory and research officer. “This is why research is the cornerstone of GIA’s mission. I can think of no better way to honor Mr. Crowningshield’s legacy.”