In the Western planetary gem tradition, the planet Jupiter is most often associated with amethyst, although secondary correspondences include sapphire and turquoise depending on which historical author is followed. The Western planetary system is the medieval and Renaissance European parallel to the Vedic Jyotish tradition and assigns one or more stones to each of the seven classical planets.

Historic sources

The Western planetary correspondences derive from late medieval and Renaissance lapidaries, including the works of Albertus Magnus and the Speculum Lapidum of Camillo Leonardi (1502). These sources do not always agree among themselves, and the Jupiter assignment in particular varies. The most consistent assignment, repeated in modern Western occult and gemmological writing, is amethyst. Sapphire is given by some sources, particularly those that follow the metal-and-stone correspondence in which Jupiter's metal is tin and Jupiter's stone is a blue or violet gem.

Amethyst as Jupiter stone

Amethyst is the purple variety of quartz, with a Mohs hardness of 7 and a refractive index of approximately 1.544 to 1.553. In Western planetary tradition it is associated with Jupiter's qualities of expansion, wisdom, philosophy and good fortune. Amethyst was historically one of the most valuable purple gems available in Europe before the discovery of large Brazilian deposits in the early nineteenth century made it widely affordable.

Modern usage

The Western planetary correspondence is used today principally in esoteric and astrological contexts rather than in mainstream retail. Where it appears in retail, it is most commonly through Jupiter or Sagittarius pendants and bracelets that incorporate amethyst. The Western planetary tradition does not have the prescriptive structure of the Vedic Jyotish system and is generally treated as decorative or symbolic rather than therapeutic.