A brief look at GIA's permanent museum exhibit at the New York lab and campus.

A large number of natural-color yellow diamonds are analyzed using grading and appearance aspects among other characteristics to clarify the differences between them and the light yellow diamonds associated with GIA's D-to-Z color grading scale.

Transparent rhodonite is considered one of the most difficult of all gems to facet because of its perfect cleavage and brittle, uneven fracture.

A large “Persian” turquoise cabochon was impregnated with a material that was also present in cavities on its base.

An emerald deposit at Byrud, in southern Norway, yielded significant quantities of crystals and gem rough in the late 19th and early 20th centuries.

By Ulla Tillander-Godenhielm, 295 pp., illus. publ. by Unicorn Press, London, 2012. US$80.00

At the Riverpark Inn show in Tucson, gem dealer Tom Schneider (San Diego, California) exhibited a parcel of kyanite displaying an unusual saturated yellowish green color.

The Carlsbad laboratory encounters a unique spessartine garnet that displays a strong color change from dark green to dark red.

Advanced testing confirms dyed material as serpentine, rather than the sugilite it was meant to imitate.

A light yellow 2.07 ct oval brilliant is the first faceted milarite examined by the Carlsbad laboratory.

Flux-grown pink synthetic sapphire displays a natural-looking inclusion scene.

Careful examination by the Carlsbad laboratory identifies both coating and clarity enhancement of an aquamarine pendant.

GIA’s laboratories are now using LA-ICP-MS to separate kornerupine from prismatine based on boron concentrations.

Recently, the Carlsbad laboratory identified a 19.68 ct gray-purple spurrite with the help of advanced testing.

An emerald specimen from Chivor hosts a large, well-formed emerald inclusion.

India’s Gem Testing Laboratory (GJEPC) encounters glass-filled CVD synthetic diamond polkis for the first time.