Research & News
Calcareous Coral and Epoxy Composite
Meticulous testing of a bangle submitted to a Taiwan gemology lab proves it to be a composite of red calcareous coral and epoxy.
GIA Knowledge Sessions
Engage in webinars on the most diverse and pressing issues in gemology today, including gemstone origin, laboratory-grown stones and new discoveries in field gemology.
Bent Rutile in Rock Crystal Quartz
Normally straight and fine, rutile needles take an unexpected bend in the polished quartz disk that is their host.
CVD Laboratory-Grown Diamond with Counterfeit GIA Inscription
A CVD laboratory-grown diamond with a fraudulent GIA inscription is submitted to the Antwerp lab.
Hole Drilled by Hand in Briolette
A centuries-old diamond featuring a hand-drilled hole inspires an investigation of the briolette cutting style and the history of drilling diamonds.
Chrysoberyl Inclusions in Flux-Grown Ruby
Natural-looking chrysoberyl crystals appear in a flux-grown ruby with a high beryllium content but lacking heat treatment.