Opals display a phenomenon known as play-of-color. When an Opal has play-of-color, it is categorized as precious opal. The main categories of precious opal are white, black, boulder, and crystal or water. Fire opal, also known as Mexican Opal, sometimes does not show play-of-color.   How Opals Formed   Opal is the result of seasonal […]

Conch “pearls,” calcareous concretions produced by the Queen conch mollusk, formerly known as Strombus Gigas or more recently as Lobatus Gigas, has mostly a very attractive pink color that may be enhanced by a characteristic silky-looking “flame structure”. Some conch “pearls” show a smooth and shiny porcelain-like luster that makes very attractive.   Although they […]

By: Diane Nicole Go, GIA Graduate Gemologist   Sapphire may be known for its blue color, but lately, its rainbow counterpart (link to Rainbow Sapphire article) has become a popular choice for candy-colored jewelry pieces. That’s because sapphires are durable and almost as hard as a diamond— and a colorful option at that.   Sapphires […]

By: Diane Nicole Go, GIA Graduate Gemologist   Red is an intense and passionate color, often associated with love, or even power and desire. It’s a prevalent color found in red roses, juicy cherries, or the life-giving blood that flows in our veins.   But when we’re talking about red gemstones, the first thing that […]

By: Diane Nicole Go, GIA Graduate Gemologist   Pearls are as mysterious as they come. Milky white with a luminescent luster that glows like the moon, they are a special form of treasure from the Earth’s lakes, seas and oceans. Many cultures associate pearls with the moon because of its spherical shape and luster, while […]