Most Russian hydrothermal synthetic rubies and pink, orange, green, blue, and violet sapphires—colored by chromium and/or nickel—reveal diagnostic zigzag or mosaic-like growth structures associated ...

This 146.10-carat peridot is in the collection of the Natural History Museum in London Peridot has always been associated with light. In fact, the Egyptians called it the “gem of the sun.” Some ...

Each year basalt-topped Peridot Mesa, on the San Carlos Apache Reservation, is a major source for thousands of carats of gem-quality peridot in sizes suitable for use in modern jewelry. Marketed ...

Amethyst may develop into the more common citrine and rarer green quartz naturally under certain geologic conditions. On the California-Nevada border, just north of Reno, amethyst, citrine, and green ...

Two major issues related to emerald are origin determination and the presence and quantity of fillers. An emerald’s value depends in part on the quality of the stone and treatments applied, so ...

Few people outside the gem industry realize the true nature of a gemstone’s journey from the mine to the counter of a store. Whether the gem is being offered to consumer’s at a traditional jewelry ...

GIA programs and courses are offered year-round on a rolling basis at GIA campuses around the globe. This enables students to jumpstart their gem and jewelry career studies at the soonest, most ...

CARLSBAD, California – December 11, 2024 – Recognizing the industry’s interest in more information about the nature of fillers in emeralds, GIA will offer filler identification with its emerald ...

The definition of padparadscha has always been debated. GIA has studied the history of the term and its modern use and indicates on a Colored Stone Identification & Origin Report when a sapphire, in ...

Established in 1931, the Gemological Institute of America (GIA) is the world’s foremost authority on diamonds, colored stones, and pearls. A public benefit, nonprofit institute, GIA is the leading ...

This amethyst crystal is from Namibia. It shows classic quartz crystal shape: a six-sided columnar crystal with a pyramid-shaped termination at the top. Courtesy Daniel Trinchillo, Fine Minerals ...

标记每个晶体边缘的切口被称为重入角。 宝石爱好者通常将其形容为“白天的祖母绿，晚上的红宝石”，亚历山大变石是金绿玉矿物中非常罕见的变色类别。 它最初在 19 世纪 30 年代被发现于 ...