Check out some of the most interesting and unusual diamonds and coloured stones submitted to GIA’s laboratories in 2019.
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 MoreThe Argyle diamond mine is the only known source of type IaB hydrogen- and nitrogen-rich diamonds coloured grey to blue to violet.
Read MoreHPHT-treated type I diamonds of various colours may exhibit unusually intense fluorescence at the facet edges and junctions.
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