Generally, all orange and red stones; stones related to the Sun and  Mars; Fire and Air-ruled stones, such as carnelian, ruby, garnet, orange calcite, diamond, tiger's  eye, topaz, sunstone, bloodstone and tourmaline.

Stones related to specific deities include:
          Aesculapius: agate
          Apollo: sapphire
          Bacchus: amethyst
          Cupid: opal
          Dionysus: amethyst
          Mars: onyx, sardonyx
          Neptune: beryl
          Odin: holed stone
          Poseidon: beryl, pearl, aquamarine
          Ra: tiger's eye
          Tezcatlipoca: obsidian


~from Maat's Books of Shadows