Natural-color saltwater cultured pearls from Pinctada margaritifera were studied by diffuse reflectance UV-Vis-NIR spectroscopy to identify the absorption features associated with their various colors ...
Two new deposits of Cu-bearing tourmaline have been found in Paraíba State, Brazil, not far from the original source at Mina da Batalha. The Glorious mine has produced a limited amount of gem-quality ...
GIA will participate in Jewellery & Gem WORLD (JGW), the world’s biggest B2B buying event, this September in Singapore. From diamonds, coloured gemstones and pearls in all qualities, colours, shapes ...
Figure 1. This 239.25 ct topaz crystal hosts some interesting inclusions of ferrocolumbite. Photo by Diego Sanchez. The author recently acquired a 239.25 ct transparent well-formed topaz crystal from ...
Pictured above, a South Sea cultured pearl containing an RFID tag, an RFID reader, and a GIA Cultured Pearl Classification Report describing the RFID reference number. Fukui Shell Nucleus Factory uses ...
Diamond is available in a range of sizes and qualities to fit every consumer's tastes. One of the first things most people learn about diamonds is that not all diamonds are created equal. In fact, ...
Cultured pearls come in different sizes, shapes, and colors. Perhaps the best-loved gems of all time, pearls—both natural and modern cultured pearls—occur in a wide variety of colors. The most ...
Heating is an accepted treatment for sapphire. But for fine-quality sapphire, confirmation from an independent laboratory like GIA that there is no evidence of heat adds to a sapphire’s rarity and ...
Since both were washed up from the sea, the words for amber and ambergris, a waxy substance secreted by sperm whales, are similar. Ambergris was the base of many perfumes in the ancient world.
As a consumer, you will regularly encounter in the marketplace gems that have been treated to change their appearance. A topic that often comes up is whether a particular gemstone is or isn’t treated.
This 5.30-carat emerald from Brazil has a slightly bluish green color. Courtesy John Parrish, courtesy African, Brazilian, Colombian Gems Incorporated. Emerald has many special qualities, but colored ...
This sapphire from Kashmir has an intense velvety blue color. – Photo: Robert Weldon/GIA. Sapphire is one of the Big three of jewelry colored gemstones—the other two are ruby and emerald. A durable ...