Coquina
Coquina (Bioclastic Limestone)
sedimentary
Category
Synthetic Or Natural Fiber
Browse synthetic or natural fiber specimens identified by the Rock Identifier community.
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Turquoise (likely Sleeping Beauty variety or treated Howlite imitation)
Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
mineral
Amethyst
SiO2 (Silicon Dioxide) - Purple variety of Crystalline Quartz
mineral
Black Onyx
Silicon dioxide (SiO2) with parallel banded structure
Mineral (variety of chalcedony)
Strawberry Quartz (or Hematoid Quartz)
Silicon Dioxide (SiO2) with inclusions of Hematite or Goethite
mineral
Precious Opal in Matrix
Hydrated Silica (SiO2·nH2O)
mineral
Sandstone (Yellow/Tan)
Clastic sedimentary rock (primarily SiO2 with iron oxide staining)
sedimentary
Amethyst Geode
Amethyst (Silicon Dioxide), Formula: SiO2
mineral
Jade (Jadeite or Nephrite)
Jadeite (NaAlSi2O6) or Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)
metamorphic
Glauconitic Sandstone (Greensand)
Glauconitic Quartz Arenite (Formula: (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
Sandstone
Arenite (SiO2 based with various mineral cements)
sedimentary
Pink Banded Agate (Dyed)
Chalcedony (cryptocrystalline silica), chemical formula SiO2
mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Gold Nugget
Native Gold (Au)
mineral
Shell Cameo
Cypraecassis rufa (Bullmouth Queen Helmet Shell)
mineraloid / biogenic specimen
Diorite (or salt-and-pepper granite pebble)
Phaneritic Igneous Rock (Intermediate Composition)
igneous
Sandstone
Sandstone (lithified quartz arenite, arkose, graywacke, etc. depending on composition)
Sedimentary Rock
Agate and Amethyst (Quartz variants)
Silicon Dioxide (SiO2) - Microcrystalline Quartz and Crystalline Quartz
mineral
Purple Banded Agate
Cryptocrystalline Quartz (SiO2)
mineral
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
metamorphic
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Amethyst
Silicon Dioxide (SiO2) with trace Iron (Fe3+)
mineral
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite
metamorphic
Schist
Mica Schist (primarily consisting of muscovite KAl2(AlSi3O10)(OH)2 or biotite K(Mg,Fe)3(AlSi3O10)(OH)2)
metamorphic
Pearl (Imitation or Cultured)
Calcium Carbonate (Aragonite/Calcite) - CaCO3
Mineraloid (Organic)
Milk Quartz (Tumbled Pebble)
Quartz (Silicon Dioxide, SiO2)
mineral
Turquoise
Hydrated phosphate of copper and aluminium - CuAl6(PO4)4(OH)8·4H2O
mineral
Unidentifiable Rock Fragment
Uncertain
Moonstone (Feldspar)
Orthoclase/Albite ((K,Na)AlSi3O8)
mineral
Blue Agate (Dyed)
Silicon Dioxide (SiO2)
Sedimentary (formed from silica deposits)
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Quartzite
Quartzite (primarily SiO2)
Metamorphic
Angel Aura Quartz (Treated Clear Quartz)
Silicon Dioxide (SiO2) coated with Vaporized Silver and Platinum
mineral
Shiva Lingam
Cryptocrystalline Quartz (Jasproid/Chalcedony mix)
sedimentary
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
Amethyst Quartz (Tumbled)
Amethyst (Silicon Dioxide with iron impurities, SiO2)
mineral
Heat-Treated Citrine (Amethyst Cathedral with Agate inclusions)
Silicon Dioxide (SiO2) with iron impurities
mineral
Chert (Arrowhead or Projectile Point)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Turquoise and Spiny Oyster (Heishi style beads)
Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Spondylus (Spiny Oyster shell)
mineral and organic gemstone