Research & News
Glass Imitation of Star Sapphire
A fixed star indicating manufactured asterism helps to identify an imitation star sapphire.
GIA Knowledge Sessions
Engage in webinars on the most diverse and pressing issues in gemmology today, including gemstone origin, laboratory-grown stones and new discoveries in field gemmology.
Quarterly Crystal: Fibers and Rods in Euclase
A well-formed euclase crystal possessed a very rare orange-pink color reminiscent of padparadscha sapphire.
Pink Aventurine Quartz with Alurgite Inclusions
A “strawberry quartz” bangle is identified as pink aventurine quartz with alurgite inclusions.
Laboratory-Grown Diamond with Internal Laser Markings
Accidental laser damage likely caused unusual internal spiral markings in a 2.44 ct CVD-grown diamond.
Honey Brown and Light Yellow Hydrogrossular
The Gem and Jewelry Institute of Thailand (GIT) identifies two samples as hydrogrossular using advanced testing techniques.