Amethyst and Citrine Anchor Quartz Family of Gems

The February birthstone, purple amethyst, is part of the quartz family, as is citrine, a heat-treated form of amethyst that shines in brilliant shades of yellow-to-orange. A recent addition to the quartz family is ametrine – a striking, dual-colored combination of these long-time favorites. Smoky quartz, which appears in neutral hues of tan and brown, is often mistaken for topaz, the November birthstone.

Transparent quartz is generally appraised for clarity, but nature has created some breathtaking exceptions. Rutilated quartz, sometimes called Venus’ Hair Stone, derives both beauty and value from titanium dioxide inclusions, which appear as intricate gold needles. Dursy quartz is revered for its covering of tiny crystals, while tourmalinated quartz has black or dark green crystals within.

Rose quartz, with its pale and feminine shade of pink, is among the most popular of quartz’s translucent varieties. Easily recognizable is the golden-yellow Tiger’s Eye, which boasts a small ray of surface light reminiscent of a feline’s glowing orb.These quartz types are all created from one large crystal. More colorful derivations arise when many microcrystals make up the mineral. Called chalcedonies, these forms are a unique and plentiful mix of banded and solid-colored agates, red-green bloodstones, and Jasper stones that look as though they’ve been painted. The popular black onyx is actually a chalcedony quartz.

In jewelry, quartz favors cabachon cuts that won’t obscure its unique features. Art cutters and stone carvers also rely on quartz to showcase their designs. They know that quartz is common, but far from ordinary.