Spessartine

Vivid orange to deep red, spessartine is the manganese aluminum garnet whose finest stones display a rich mandarin hue—vivid orange material from the Loliondo deposit of Namibia is marketed as Mandarin Garnet. The Hollandine Mine of Nigeria, together with deposits in Namibia and Tanzania, has yielded some of the world's finest orange garnets, and the variety has grown fashionable in contemporary jewelry. Strong dispersion and brilliant orange fire make spessartine one of the most striking members of the garnet family, while a Mohs hardness of 7 to 7.5 gives it the durability expected of the group. It crystallizes in the isometric system and carries an unusually high refractive index near 1.79 and a specific gravity of about 4.12, reflecting its manganese-rich composition.