Demantoid

A sub-variety of andradite and the moat valuable of the garnets, the colour ranges from dark green (hence sometimes miscalled “Uralian emerald”) to yellowish-green (hence sometimes miscalled “olivine”). It is the most expensive and rare of garnet gemstones.

It has many similarities with the diamond (“demant”), hence its name (meaning ‘diamond-like’), but it has low hardness, so that it is not suitable for hard wear as jewellery. The stones have inclusions of fine asbestos fibers (byssolite) that are sometimes called ponytails.