Studies carried out at the DTC Research Centre have shown that single-crystal CVD synthetic diamond is clearly distinguishable from natural diamond. This article presents information about the CVD ...

Learn the product knowledge and grading skills to effectively buy inventory and build confidence when buying and selling akoya, South Sea, Tahitian and freshwater pearls. You will be taught GIA’s 7 ...

Miners collect spinels from gravel at the end of a long day at Man Sin. Photo by Vincent Pardieu, © GIA. In the spring of 2001, I was studying gemology in Yangon ...

Gem-quality synthetic diamond crystals weighing up to 11 ct have been grown in limited numbers at the De Beers Diamond Research Laboratory since the 1970s. These crystals have been produced strictly ...

With proper care, citrine is a beautiful and versatile gemstone for jewelry use. – Robert Weldon Gem and mineral hardness is measured on the Mohs scale. The numbers are based on the relative ease or ...

Below is the list of recognized holidays when GIA locations will be closed.

Consumers now, more than ever, have a heightened awareness of sustainably and ethically sourced products. The GIA Diamond Origin Report uses scientific evaluation to provide confirmation of a ...

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 ...

Figure 1. This 2.54 ct yellowish green spinel is shown under daylight conditions (left) and short-wave UV light (right). Photos by Sood Oil (Judy) Chia (left) and Jian Xin (Jae) Liao (right).

Raman spectroscopy confirmed the identity of the material as pezzottaite by an intense peak at ~1100 cm –1, which is not present in beryl. Fourier-transform infrared spectroscopy showed features ...

Diamonds are known for their hardness – their ability to resist scratches and abrasions. But diamonds are not impervious to damage, since their hardness is uneven along different crystal directions.

Figure 1. Glass in a silver brooch, hallmark from 1866. Private collection, photo by Jaroslav Hyršl. Tectites are members of a large group of impact glasses, formed by the collision of a meteorite on ...