CARLSBAD, Calif. – June 2, 2025 – Beginning later this year, GIA (the Gemological Institute of America) will start using descriptive terms to characterize the quality of laboratory-grown diamonds and ...

GIA’s Mumbai laboratory recently received an undrilled white semi-baroque saltwater nacreous pearl for identification, weighing 8.98 ct and measuring 11.31 × 10.75 × 10.30 mm (figure 1). Externally, ...

The authors recently examined a 1.80 ct greenish blue sapphire and were surprised to observe a dark red internal protuberance jutting inward from the surface of the pavilion (see above). The prismatic ...

This large Australian light opal cabochon weighs 117.85 carats. Small play-of-color flashes of orange and green predominate in a pinfire pattern, with spots of a more muted blue over a grayish ...

Figure 1. The bright red faceted ruby in this gold ring is from the large and potentially productive Snezhnoe deposit in Tajikistan. Photo by Zamoniddin Z. Nasriddinov. Discovered during the late ...

View the holiday schedule for all GIA locations worldwide.

Jadeite is 6.5 to 7, and nephrite is 6 to 6.5 on the Mohs hardness scale. Hardness and toughness Gem and mineral hardness is measured on the Mohs scale. The numbers are based on the relative ease or ...

Use the form below to submit a request to list your location on the GIA Retailer Lookup. Have multiple locations? Use the multi-store tool to make registration easier.

Figure 1. Sapphires from a variety of sources. Faceted stones (left to right): 6.36 ct pink/orange (padparadscha), 1.63 ct pink, 4.76 ct violet, 5.43 ct violet purple, 3.03 ct blue, 2.12 ct blue, 8.06 ...

The sparks will fly − and your diamond will shine − when you follow these cleaning tips. Diamond is the hardest natural substance on Earth. It can cut any kind of rock or metal, but only another ...

Descending into Peshawar for the first time, a foreign tourist might be surprised to learn that amid the clutter of buildings in this historical city lies an important gem trading center. This market ...

The Imperial Flame, a superb natural color Brazilian topaz, was fashioned from a 615 ct crystal recovered over 20 years ago. The finished piece measures 89.53 × 20.56 × 19.15 mm and weighs 332.24 ct.