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New mineral named after famed gemmologist

At left is a diamond sample containing crowningshieldite in the dark area circled in red. At right is an enlargement from an electron microscope in which individual grains of crowningshieldite are seen in a fine grained mixture with other minerals. Photos © Evan M. Smith (left) and Fabrizio Nestola (right)
At left is a diamond sample containing crowningshieldite in the dark area circled in red. At right is an enlargement from an electron microscope in which individual grains of crowningshieldite are seen in a fine grained mixture with other minerals.
Photos © Evan M. Smith (left) and Fabrizio Nestola (right)

Renowned researcher G. Robert Crowningshield became part of the gemmological landscape in a new way at the Gemological Institute of America’s (GIA’s) International Gemological Symposium yesterday. A newly discovered mineral has been named ‘crowningshieldite’ in his honour.

The new find is believed to form from alteration or chemical modification of metallic, polyphasic inclusions in diamonds. A nickel sulphide mineral with a hexagonal crystal structure, it was found over the course of GIA research focused on inclusions in Cullinan-like, large, inclusion-poor, pure, irregular, and resorbed (CLIPPIR) diamonds.

Evan M. Smith, the GIA research scientist who led the project, presented the mineral at the symposium and announced it at the institute’s annual research meeting.

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

Crowningshield can lay claim to numerous gemmological achievements, beginning in 1956 with the discovery of the spectroscopic feature characterizing irradiated yellow diamonds. He also made strides in the realm of lab-grown diamonds, having observed identification criteria (such as colour zoning, metallic inclusions, and uneven patterns of ultraviolet [UV] fluorescence) still relied upon today. Crowningshield also wrote a wide variety of columns and reports throughout the years, focusing on everything from Padparadscha sapphires to pearls and coloured stones.

The International Mineralogical Association (IMA) accepted crowningshieldite as a mineral in mid-September. GIA will display a specimen at its museum in Carlsbad, Calif.

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