Crystals
Carnelian
Chalcedony variety SiO2 Microcrystalline quartz Mohs approximately 6.5–7 Iron-colored orange to red Translucent internal glow No cleavage Carnelian: Iron-Colored Chalcedony, Translucent Ember Light, and the Art of the Seal Carnelian...
Carnelian
Chalcedony variety SiO2 Microcrystalline quartz Mohs approximately 6.5–7 Iron-colored orange to red Translucent internal glow No cleavage Carnelian: Iron-Colored Chalcedony, Translucent Ember Light, and the Art of the Seal Carnelian...
Hematite
Iron(III) oxide Fe2O3 Trigonal crystal system Mohs approximately 5–6.5 Specific gravity approximately 5.0–5.3 Red to red-brown streak Metallic to earthy luster Major iron ore and historic pigment mineral Hematite: The...
Hematite
Iron(III) oxide Fe2O3 Trigonal crystal system Mohs approximately 5–6.5 Specific gravity approximately 5.0–5.3 Red to red-brown streak Metallic to earthy luster Major iron ore and historic pigment mineral Hematite: The...
Garnet
Garnet mineral family X3Y2(SiO4)3 Cubic crystal system Mohs approximately 6.5–7.5 No cleavage Red, orange, yellow, green, violet, black Tsavorite and demantoid Spessartine and hessonite Garnet: The Mineral Family Beyond Red...
Garnet
Garnet mineral family X3Y2(SiO4)3 Cubic crystal system Mohs approximately 6.5–7.5 No cleavage Red, orange, yellow, green, violet, black Tsavorite and demantoid Spessartine and hessonite Garnet: The Mineral Family Beyond Red...
Labradorite
Plagioclase feldspar Approximately An50–An70 (Ca,Na)(Al,Si)4O8 Triclinic crystal system Mohs approximately 6–6.5 Two cleavages near 90 degrees Directional labradorescence Blue, green, gold, orange, and violet flash Spectrolite and rainbow moonstone Labradorite:...
Labradorite
Plagioclase feldspar Approximately An50–An70 (Ca,Na)(Al,Si)4O8 Triclinic crystal system Mohs approximately 6–6.5 Two cleavages near 90 degrees Directional labradorescence Blue, green, gold, orange, and violet flash Spectrolite and rainbow moonstone Labradorite:...
Lava
Informal rock name Usually vesicular basalt or scoria Extrusive igneous material Frozen volcanic gas bubbles Black, charcoal, brown, and red Vesicular or amygdaloidal texture Landscape, architectural, and lapidary use Rock...
Lava
Informal rock name Usually vesicular basalt or scoria Extrusive igneous material Frozen volcanic gas bubbles Black, charcoal, brown, and red Vesicular or amygdaloidal texture Landscape, architectural, and lapidary use Rock...
Meteorite
Extraterrestrial geological material Mostly fragments of asteroids Stony, stony-iron, and iron groups Oldest solids approximately 4.567 billion years Fusion crust and atmospheric ablation Iron-nickel metal in many types Chondrules, olivine,...
Meteorite
Extraterrestrial geological material Mostly fragments of asteroids Stony, stony-iron, and iron groups Oldest solids approximately 4.567 billion years Fusion crust and atmospheric ablation Iron-nickel metal in many types Chondrules, olivine,...