Explore diamond history, research, quality factors, and more in the GIA Gem Encyclopedia.

Explore aquamarine history, research, quality factors, and more in the GIA Gem Encyclopedia.

Sally Eaton-Magaña, Christopher M. Breeding, and James E. Shigley ...

We present an algorithm for enumerating all possible faceting arrangements of dihedrally symmetric diamond cuts. We first separate the question into enumerating crowns a ...

Basic, intermediate, and alkaline igneous rocks can sometimes also display similar pegmatitic textures. They include pegmatitic gabbro, syenite, and nepheline syenite, all of which are composed of ...

De Beers Group and GIA today announced the signing of a definitive agreement for GIA to acquire a 30 per cent shareholding in Tracr.

Figure 1. These examples of gem minerals that formed in magmatic environments are part of GIA’s Eduard Gübelin Collection. From top to bottom and left to right: 29.96 ct sanidine feldspar from Germany ...

Such was the setting for the arrival of Art Deco – a style that celebrated the machine age. Sleek ocean liners, streamlined trains, and towering skyscrapers were favorite images to express this: they ...

Optical brightening agents (OBAs) are chemical compounds that can absorb light in the ultraviolet and violet region of the electromagnetic spectrum and emit light in the blue region as fluorescence, ...

Diamond is a metasomatic mineral that forms during migration of carbon-bearing fluids, which means that it forms from fluids and melts that move through the mantle. Diamonds can form in both ...

Blue zircon is perhaps best known from Cambodia, with most if not all of the material recovered as brown stones that turn blue upon heating. Recently, Brent Smith of Phoenix Gems supplied us with a ...

Figure 1. The black manganese oxide “plumes” in this Australian opal serve as a good example of art and science merging in gemology. Photomicrograph by Nathan Renfro, field of view 5.85 mm. Note: ...