Amethyst is the purple variety of the quartz mineral species and the gem most commonly associated with the color purple.

Learn about the factors that make amber so desirable.

Amber formed tens of millions of years ago, when sap from ancient trees hardened and fossilized.

Citrine—the transparent, pale yellow to brownish orange variety of quartz—is rare in nature. In the days before modern gemology, its tawny color caused it to be confused with topaz.

珠宝行业使用特定术语描述人造的和外观相似的宝石，即合成材料和类似石。它们之间的差别十分微妙，但极其重要。合成材料是指与天然宝石材料具有相同的化学组成、晶体结构以及光学特性和物理特性的人造材料。除此之外，还有一些材料本身看起来就像天然宝石。这些材料被称为类似石或仿品，可以是天然的，也可以是人造的。而替代品则是老术语，与类似石或仿品意思相同。

以下为 GIA 根据规定节假日安排的课程表，部分上课日将延长至下午 4 点，以便学生假日休息。

At age 79, Bob Halem loves reminiscing about the serendipity that brought him into the world of colored stones.

Bridges reflects on his father’s life and work, which led him from his native Scotland to Africa, where he made his mark in the gem world with the discovery of tsavorite. For all the fame the discovery brought him, it seemed cursed from the start.

Mr. Pavlik started out buying and selling cut gems, then added gem cutting to his skill set with a stint in the famed cutting center of Idar-Oberstein. Eventually, he turned to liquidation of others’ excess and unused gem materials. Now, he travels the world to seek gems that, for one reason or another, haven’t sold, and matches those “unwanted” products with the right buyer.

Dudley Blauwet, a colored gemstone dealer from Colorado, has been traveling throughout Asia and parts of Africa for three decades, hunting down good, saleable gem material.

In an exclusive interview with Edward Boehm at the 2013 Tucson Gem Show, GIA uncovers a rich vein of current information on supply and demand in the rare and high-end gem market.

It’s an emotional roller coaster following veteran gem dealer Evan Caplan in this exclusive GIA interview conducted at the 2013 Tucson Gem Show.

Jeff Mason provides us with a fascinating look into a sometimes-misunderstood gem and its often-unpredictable market.

Jeff Mason provides us with a fascinating look into a sometimes-misunderstood gem and its often-unpredictable market.

Nomad’s specializes in a wide range of high-end colored stones such as spinel, tourmaline, peridot, garnet, and corundum, all untreated. Saltzman finds that trade shows are excellent places for educating consumers about the differences between treated and untreated stones.

The range of Tanzanian gems’ lovely colors — both natural and slightly treated — is Mr. Sevdermish’s particular passion.

For some time, Brazil was considered the sole legitimate source of the electric-blue tourmaline known as Paraíba. As a result, Mr. Konate and his company met considerable resistance when they first started mining similar material in Mozambique.

Paula Crevoshay’s one-woman exhibit of her jewelry designs at the Carnegie Museum in Pittsburgh speaks for her esteemed status in the jewelry world. In this GIA exclusive interview recorded at the 2013 Tucson Gem Show, she speaks for herself and her art in eloquent and compelling detail.

In an exclusive interview with GIA conducted at the 2013 Gem Show in Tucson, Rajneesh Bhandari pulls back the curtain on the too-often secretive world of gemstone treatments.