Hessonite, the Cinnamon Stone of Rahu

Hessonite is the orange-brown to cinnamon variety of grossular garnet, a calcium aluminium silicate, its colour owed to iron and manganese. Under magnification it characteristically shows a swirled, treacly or heat-wave internal texture from rounded crystal inclusions, a feature diagnostic enough that gemmologists use it to identify the stone.

The name comes from Greek hesson, inferior, because it is slightly softer and less dense than other garnets. Its most important traditional role is in jyotisha, where under the name gomeda it is the gem of Rahu, the ascending lunar node, and one of the nine navaratna stones; the astrological literature prescribes it specifically for Rahu's influences. This is a documented and continuous tradition. The broader properties attributed to hessonite in general crystal books, dispelling confusion, protection against hidden enemies, restate the jyotisha character of Rahu in the modern metaphysical vocabulary.