Hessonite

The name carries a small insult. It comes from the Ancient Greek hēssōn, meaning inferior — a nod to the stone being softer and lighter than most other garnets. Hessonite is the orange to cinnamon-brown gem variety of grossular, a calcium-aluminium garnet. Its older name says the same thing about that colour: it is the cinnamon stone. Gem cutters had long mistaken it for a lesser kind of zircon, the gem it most resembles in its reddish, orange-leaning glow.

In the gem traditions of India it was never treated as inferior at all. There it is the gomeda, one of the nine stones of the navaratna — a set of nine gems, each tied to a celestial body. Hessonite is the gem of Rahu, the ascending lunar node, and on that account it has long been cut and worn across South Asia.

The clearest sign of how often the stone went unrecognised in the West came from the British chemist Arthur Herbert Church. He showed that many engraved gems long taken for zircon were in fact hessonite. The mistake is an easy one: the two share a warm reddish fire, and only a careful eye separates them.

Hessonite has no industrial use. It is valued only as a gemstone — the orange to cinnamon-brown variety of grossular garnet, cut and faceted for rings and other jewellery. Most of it reaches the trade from Sri Lanka and India. There it is recovered chiefly from placer deposits — loose gravels where the heavy crystals collect after weathering out of their parent rock. Smaller amounts come from Brazil and California. In South Asia it remains in steady demand as the gomeda, the gem of the planet Rahu and one of the nine stones of the navaratna.