The little black dress of gemstones, opaque black onyx takes on extra polish in eye-catching faceted cuts. It has the look of black diamond for less. Black onyx is the 7th anniversary gem and the zodiac gem for the sign of Leo.
This basic black gem first became popular in Victorian times, when demand for mourning jewelry led jewelry designers to look for all-black gemstones.
Ancient Greek philosopher Pliny recommends soaking dark-colored quartz in sugar water for weeks, then plunging it into acid, turning the sugar to carbon and blackening the stone. That's how black onyx was born. Today, more modern methods can be used to create the even black tone of black onyx but some still prefer the ancient technique.
Black onyx is often seen in jewels of the Art Deco period, the perfect foil for diamond in black and white geometric designs.
Like all quartz varieties, black onyx is durable and suitable for everyday wear. Clean with mild dish soap: use a toothbrush to scrub behind the stone where dust can collect.