Kornerupine: Kornerupine is a rare magnesium aluminum borate silicate which occurs as transparent prismatic cryst... (read full)

Jet Lignite: Jet is an organic gem material composed of lignite, and is a bituminous coal which can be polished. ... (read full)

Jasper Chalcedony: Jasper is the opaque form of Chalcedony, the microcrystalline varieties of quartz that form concreti... (read full)

Jadeite: Jadeite is a silicate of sodium and aluminum, and is a member of the Clinopyroxene group of minerals... (read full)

Ivory: Ivory is an organic gem material, largely obtained from the tusks of African and Indian (Asiatic) el... (read full)

Iolite: Iolite is the violet-colored variety of Cordierite (named after French geologist P. Cordier), a sili... (read full)

Indicolite: Indicolite is the blue sodium-rich variety of Tourmaline, and may come in all shades of blue, from l... (read full)

Hypersthene: Hypersthene is an important iron-rich orthopyroxene in the Pyroxene group with an orthorhombic cryst... (read full)

Howlite: Howlite an opaque, massive mineral used for ornamental and utilitarian articles. is a rarity for col... (read full)

Hessonite: Hessonite is the brown-orange variety of Grossular, a nesosilicate in the Garnet group, with an isom... (read full)