What is Demantoid?
Demantoid is the vivid green gemstone variety of andradite garnet, valued for its dispersion, natural inclusions and classic collector localities.
Mineralogy and structure
The reference formula is Ca3Fe2(SiO4)3. Demantoid is a variety of andradite rather than a separate mineral species; its cubic garnet structure is the structure of the host mineral.
Colour and appearance
Typical colours include green, yellow-green. Its dodecahedral, granular habit and vitreous lustre are useful descriptive features, but colour alone is not diagnostic.
Formation and localities
Demantoid forms in or is associated with contact-metamorphic skarns and serpentinite-related environments. Important documented localities include the Urals in Russia, Namibia, Madagascar, Italy and Pakistan.
Collecting and care
Demantoid is best kept as a labelled reference or collector specimen. Protect fragile crystals from impact and avoid cutting or grinding unknown material. Lead-, arsenic-, vanadium- and copper-bearing specimens are for display and careful handling only.
Demantoid in popular symbolism
Some modern crystal guides associate Demantoid with zodiac signs or symbolic themes based on colour, locality or collecting tradition. These associations vary between sources and are cultural interpretations, not mineralogical or medical properties.
