Photo courtesy of Scott Papper, GIA GG, AJP, CM (NAJA), Global Gemology & Appraisals
Group: Garnet Mohs Hardness: 6.5 to 7.5 out of 10 Color: Nearly all colors RI: 1.714 to 1.888 Birefringence: None SR/DR/AGG: SR, often with ADR Pleochroism: None SG: 2.72 (+0.18 / -0.05)
garnet facts
Photo courtesy of Scott Papper, GIA GG, AJP, CM (NAJA), Global Gemology & Appraisals
Garnets occur in various colors including red, orange and green. A garnet bead necklace, that was found in an Egyptian grave, is dated to 3800 B.C.
Most red garnets, while beautiful, are not terribly valuable due to their relative abundance. Green tsavorite garnets, however, can be much more expensive, especially in larger sizes. Garnet is a January birthstone and is the 2nd wedding anniversary gemstone.
Photo courtesy of Sotheby's
garnet varieties
almandine
Photo courtesy of Scott Papper, GIA GG, AJP, CM (NAJA), Global Gemology & Appraisals
Color Generally dark toned brownish orange to brownish red to purplish red, with low saturation.
Magnification Needle-like inclusions that intersect at 70° and 110° in the same plane. High- and low-relief crystals. Zircon crystals with strain halos.
Spectrum 3 strong bands in the green and yellow at 505, 527 & 575nm
Fluorescence Inert
spessartine
Photo courtesy of Scott Papper, GIA GG, AJP, CM (NAJA), Global Gemology & Appraisals
Color Orange, brownish orange, yellowish orange or red orange. Always has an orange component and never shows any purple.
Spectrum Bands at 412, 424 & 432nm, which sometimes merge to form a cutoff. Bands at 505, 527 & 575nm.
Fluorescence Inert
pyrope
Photo courtesy of Scott Papper, GIA GG, AJP, CM (NAJA), Global Gemology & Appraisals
Color Medium to dark reddish orange, red through slightly purplish red to pale pink
Magnification Needle-like inclusions and irregular rounded crystals.
Spectrum Chrome Pyrope: Band at 505nm plus broad absorption at 520 through 620nm. Possibly fine lines in the red at 685 & 687nm. Cutoff around 490nm. None Chrome Pyrope: Only the 505nm band and a cutoff at 490nm.
Fluorescence Inert
rhodolite
Photo courtesy of Scott Papper, GIA GG, AJP, CM (NAJA), Global Gemology & Appraisals
Color Must have a purplish component
Magnification Needle-like inclusions that intersect at 70° and 110° in the same plane. High- and low-relief crystals. Zircon crystals with strain halos.
Spectrum 3 strong bands in the green and yellow at 505, 527 & 575nm
Fluorescence Inert
demantoid (andradite)
Photo courtesy of Gems by Nomads
Color Green through yellow green, with strong fire