Check out some of the most interesting and unusual diamonds and coloured stones submitted to GIA’s laboratories in 2019.
Read MoreThe Argyle diamond mine is the only known source of type IaB hydrogen- and nitrogen-rich diamonds coloured grey to blue to violet.
Read MoreKnowledge of type allows gemmologists to better evaluate if a diamond might be treated or synthetic, and whether it should be sent to a laboratory for testing.
Read MoreUsing a multi-step process, Lucent Diamonds has developed a new treatment process for certain natural diamonds that creates colours from pink-purple to red to orangey brown.
Read MoreThis section, from the Spring 1991 issue of Gems & Gemmology, is a compilation of interesting finds from GIA’s laboratories.
Read MoreHPHT-treated type I diamonds of various colours may exhibit unusually intense fluorescence at the facet edges and junctions.
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