Natural Red Rhodolite Garnet Faceted Tear Drops Length is 4.5 Inches & Sizes from 6mm to 7mm Approx. Garnets /???rn?t/ are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives. Garnets /???rn?t/ are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives.The different species are pyrope, almandine, spessartine, grossular (varieties of which are hessonite or cinnamon-stone and tsavorite), uvarovite and andradite.