TABLE VIII
Reading edition
Degrees of Hardness of Gem-Stones
5. Kyanite (5–7), apatite, lapis lazuli
5½. Enstatite, beryllonite, sphene
6. Opal, moonstone, turquoise, diopside
6½. Spodumene, peridot, garnet (demantoid), benitoite, idocrase, epidote, axinite, jade (nephrite)
7. Iolite, quartz, tourmaline, jade (jadeite)
7¼. Garnet (hessonite, pyrope)
7½. Beryl, garnet (almandine), zircon, phenakite, euclase, andalusite
8. Topaz, spinel
8½. Chrysoberyl
9. Corundum
10. Diamond