Black onyx and black spinel

Two stones, one color, told apart by weight and light.

On the tray, a strand of black onyx reads as one unbroken color, the facets catching light in small flat planes with no gray creeping in at the edges. Black spinel sits next to it and looks glassier, the light coming back harder off each facet, and the strand feels heavier in the hand than its size suggests. Makers reach for both when a piece needs a hard stop, a line of true dark against silver, brass, or pale stone.

Where it comes from

Onyx is a chalcedony, itself a microcrystalline form of quartz, and in its banded black-and-white form it belongs to agate. Those straight, nearly parallel layers made it the great engraving stone of antiquity: carvers cut down through one band into the next to raise a pale figure against a dark ground. The Gemma Claudia, a Roman five-layer cameo of about the year 49 now in the Kunsthistorisches Museum, shows how far that patience went. Solid black chalcedony, without banding, became the traditional black gemstone for jewelry. Black spinel is a different mineral entirely, magnesium aluminum oxide, and comes from Thailand, Myanmar, and Sri Lanka. Spinel's larger crystals from southeast Asian mines passed through the hands of kings and emperors, and for centuries red spinel wore the name ruby in Europe's crown jewels, among them the Black Prince's Ruby and the Timur Ruby. Our strands are cut in Jaipur, India, and chosen strand by strand here in Cupertino, California.

What tradition says

Few stones carry as much unhappy lore as onyx. Old writers tied it to quarrels, bad dreams, and gloom, and for centuries people looked for ways to counter those purported effects rather than set the stone aside, since they liked the look of it too much to give it up. Alongside that darker reading runs a steadier one: in crystal tradition both black onyx and black spinel are called protective, grounding stones, held to steady the wearer and turn away what is unwanted. It is said that a dark stone worn close keeps a person in their own footing. All of this is tradition and belief, not fact.

These are beliefs people have held about the stone, told as tradition. They are not claims, and not advice.

How makers use it

Faceted marquise, daggers, and rondelles move fastest, and they suit different work. An 11mm rondelle strand strings straight into a plain necklace or spaces out a bracelet, and 10x40mm daggers make a fringe that hangs with real weight. Onyx anchors men's pieces and minimalist lines where one dark shape does all the talking. Spinel earns its place when you want natural black at fine-jewelry hardness, and it holds its own beside diamonds and gold. We keep fourteen onyx strands and six spinel, faceted and smooth, in marquise, pear, kite, tube, bar, and dagger from 15 to 45mm.

Looking after it

Both stones take daily wear without fuss, and both are safe in an ultrasonic cleaner. Keep onyx away from household cleaners and solvents. Warm water, mild soap, and a soft brush at the drill holes are enough. Store strands so the pointed shapes are not knocking against harder stones.

Sources: Onyx Symbolism and Legends - International Gem Society, Onyx Properties, Varieties, and Jewelry Information - Gem Society, Onyx | Gemstone, Chalcedony, Agate | Britannica, Onyx