RELATIVE SPECIFIC GRAVITY OF PRECIOUS STONES.
First rank, 5+ . . . Crocoite.
Second rank, 4+ . . Barite, hematite, magnetite, marcasite, monazite, pyrite»
rutile, zircon.
Third rank, 3+ . . . Axinite, azurite, chlorastrolite, chondrodite, chiastolite
(andalusite), crocidolite, chrysolite, chrysoberyl, corundum, diamond, diaspore, diopside, dioptase, epidote,
euchroite, euclase, garnet, hiddenite, hypersthene, Jadeite, kyanite, malachite, octahedrite, rhodocrosite, spinel,
spodumene, titanite, topaz, vesuvianite (or idocrase),
willemite, zonochlorite.
Fourth rank, 2+ . . Adularla, agalmatolite, amazon-stone, apophyllite, beryl,
bowenite, calcite, iolite (or dichroite), jade (or nephrite),
labradorite, lapis-lazuli, lepidolite, moonstone, obsidian,
phenakite, quartz, serpentine, selenite, steatite, sunstone,
thomsonite, tourmaline, turquoise, vulpinite, williamsite..
Fifth rank, 1+ . . . Amber, jet, opal.
