Smoky Quartz Oval Hammered Ring, Size 6

Non-toxic and safe to handle. At hardness 7 it is durable for everyday wear and water-safe for brief rinsing, but prolonged sunlight or heat can fade its color. Very black, fully opaque pieces are often artificially irradiated; choose naturally formed stones.

Smoky Quartz begins as ordinary quartz growing in granite and pegmatite. Over long stretches of geological time, gamma radiation from the surrounding rock acts on trace aluminium in the crystal, creating color centers that deepen it from clear to tan, brown and near-black. It forms worldwide, with celebrated sources in the Cairngorm Mountains of Scotland, the Swiss Alps, the pegmatites of Brazil and Madagascar, and Colorado.

Smoky Quartz is a macrocrystalline variety of quartz, silicon dioxide (SiO₂), crystallizing in the trigonal system. Its brown-to-black color comes from natural gamma irradiation acting on aluminium impurities in the lattice, forming light-absorbing color centers; heating above roughly 200 to 300 °C or strong UV exposure can fade it. It has a vitreous luster, ranges from transparent to translucent, and registers 7 on the Mohs scale. Very dark, fully opaque material is often artificially irradiated.

• In 12th-century China, flat panes of smoky quartz called ai tai, meaning dark clouds, were worn as early sunglasses, and judges are said to have used them to hide their expressions while questioning witnesses.
• In Scotland the stone took the name Cairngorm from the mountains where it was gathered, and it was set into brooches, kilt pins and the hilts of dirks and sgian-dubhs as a proud emblem of Highland dress.
• The name Morion, still used for the darkest smoky quartz, comes from a misreading of mormorion, a dark stone described by Pliny the Elder in his Natural History nearly two thousand years ago.