Gemstone education

Reference guide to gemstones

Alexandrite

It’s the color-change variety of the mineral, chrysoberyl. Bluish green in daylight, purplish red under incandescent light; hard and durable.

Amber

Fossilized resin, color of the burnished sun–orange or golden brown. Amber might trap and preserve ancient life, including insects.

Amethyst

Purple variety of the mineral quartz, often forms large, six-sided crystals. The birthstone for February, the name of the gem comes from a Greek word that means "not drunk."

Citrine

Citrine’s color comes from traces of iron. It’s perhaps the most popular purchased yellow gemstone and an attractive alternative for topaz and yellow sapphire.

Ametrine

Ametrine, one of the rarest types of transparent quartz, combines two colors: amethyst’s purple and citrine’s orange-to-yellow.

Aquamarine

Blue to slightly greenish-blue variety of the mineral beryl. Crystals are sometimes big enough to cut fashioned gems of more than 100 carats.

Diamond

This hardest gem of all is made of just one element: carbon. It’s valued for its colorless nature and purity. Most diamonds are primeval—over a billion years old—and form deep within the earth.