Crystals
Chalcedony
Microcrystalline silica SiO2 Quartz with moganite Mohs approximately 6.5–7 No cleavage Waxy to vitreous luster Translucent to opaque Chalcedony: Mist-Lit Quartz, Ancient Carving Stone, and a Family of Many Forms...
Chalcedony
Microcrystalline silica SiO2 Quartz with moganite Mohs approximately 6.5–7 No cleavage Waxy to vitreous luster Translucent to opaque Chalcedony: Mist-Lit Quartz, Ancient Carving Stone, and a Family of Many Forms...
Diopside
Clinopyroxene mineral CaMgSi2O6 Monoclinic crystal system Mohs approximately 5.5–6.5 Two cleavages near 90 degrees Chrome-green gem variety Four-ray star variety Violet violane variety Diopside: Chrome-Green Pyroxene, Alpine Marble, and Four-Ray...
Diopside
Clinopyroxene mineral CaMgSi2O6 Monoclinic crystal system Mohs approximately 5.5–6.5 Two cleavages near 90 degrees Chrome-green gem variety Four-ray star variety Violet violane variety Diopside: Chrome-Green Pyroxene, Alpine Marble, and Four-Ray...
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:...