Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Category
Sedimentary (Man Made Composite)
Browse sedimentary (man made composite) specimens identified by the Rock Identifier community.
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Moonstone
Orthoclase Feldspar (formula: (K,Na)AlSi3O8)
mineral
Diamond (as set in a metal alloy ring)
Diamond (Pure Carbon, C)
mineral
Grey Granite
Phaneritic Felsic Intrusive Igneous Rock
igneous
Pearl (Biogenic)
Nacre / Calcium Carbonate (CaCO3)
mineral
Obsidian
Volcanic Glass (Amorphous SiO2)
igneous
Sunstone
Aventurine Feldspar (Plagioclase Feldspar with inclusions)
mineral
Diamond
Carbon (C)
mineral
Goldstone and Aura Quartz
Cuprous Glass (Goldstone) and Titanium-coated SiO2 (Aura Quartz)
Mineral/Glass Specimen
Granite
Phaneritic Igneous Rock (composed mostly of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Granite
Phaneritic plutonic rock (SiO2 typically >69%)
igneous
Amethyst Cluster
Silicon Dioxide with Iron impurities (SiO2)
mineral
Tree Agate
Chalcedony (SiO2)
gemstone
Industrial Slag
Anthropogenic Vitreous Slag
igneous
Amber
Succinite (Carbon-based organic compound; approximate formula C10H16O)
Mineraloid
Diamond (Cut Gemstone)
Natural Carbon (C)
gemstone
Diamond (Faceted)
Carbon (C)
gemstone
Diamond
Diamond (pure Carbon, C)
mineral
Granite
Phaneritic Plutonic Felsic Rock
igneous
Granite
Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)
igneous
Turquoise bead bracelet
Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O
mineral
Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)
N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)
Organic (if resin) or Synthetic (if glass); simulating Sedimentary or Metamorphic (for natural stones)
Chert (Jasper Variant likely)
Silicon Dioxide (SiO2)
Sedimentary Rock or Mineral (depending on origin and purity)
Blue opalite (often sold as synthetic opal)
Opalite glass; amorphous hydrated silica if natural opal (SiO₂·nH₂O)
gemstone
Quartzite Pebble
Quartzite (SiO2)
metamorphic
Slate
Metamorphic pelitic rock
metamorphic
Angel Aura Quartz (Treated Clear Quartz)
Silicon Dioxide (SiO2) coated with Vaporized Silver and Platinum
mineral
Desert Rose (Barite Rose / Gypsum Rose)
Barium Sulfate (BaSO4) or Hydrous Calcium Sulfate (CaSO4%22H2O)
mineral
Carved quartz (likely rose quartz and green aventurine/quartz)
Quartz, silicon dioxide (SiO₂); green material may be aventurine quartz or serpentine
gemstone
Diamond (or Diamond Simulant)
Carbon (C)
mineral
Polished serpentine pendulum
Serpentine-group minerals, chiefly antigorite/lizardite; approximate formula Mg₃Si₂O₅(OH)₄
metamorphic
Granodiorite with Quartz Veining
Granodiorite (containing Plagioclase Feldspar, Quartz, and Biotite/Hornblende) with Quartz (SiO2) veins
igneous
Quartzite
Quartzite (SiO2)
metamorphic
Pink Marble
Recrystallized Limestone (Calcium Carbonate, CaCO3)
metamorphic
Native Silver
Silver (Ag)
mineral
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2
Mineral
Crackled Quartz (Blue Dyed)
Silicon Dioxide (SiO2) with anthropogenic dye
mineral
Pearl (with Peridot)
Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4
mineral
Quartzite
Quartzite (SiO2)
metamorphic
Common Marble
Calcium Carbonate (CaCO3)
metamorphic
Blue Quartz (Aventurine)
Silicon Dioxide (SiO2) with fibrous inclusions (commonly Dumortierite)
mineral
Petoskey Stone
Hexagonaria percarinata
fossil