Mother of Pearl (Nacre)
Aragonite (layered with organic polymers), CaCO3
Category
Browse sedimentary or igneous (secondary formation) specimens identified by the Rock Identifier community.
Mother of Pearl (Nacre)
Aragonite (layered with organic polymers), CaCO3
Stichtite (often found in Serpentinite)
Stichtite Mg6Cr2CO3(OH)16·4H2O
Blue Aventurine
Silicon Dioxide (SiO2) with inclusions of Dumortierite
Shiva Eye Shell (Operculum)
Calcium Carbonate (Aragonite), CaCO3
Prase Quartz on Feldspar
Quartz (Silicon Dioxide, SiO2) with Hedenbergite inclusions on Potassium Feldspar (KAlSi3O8)
Tree Agate
Silicon Dioxide (SiO2) with Dendritic Inclusions
Moss Agate
Chalcedony (Silicon Dioxide / SiO2)
Moss Agate
Silicon Dioxide with inclusions (SiO2)
Iron-Nickel Meteorite fragment
Siderite (meteoritic iron), composed primarily of Kamacite (α-(Fe,Ni)) and Taenite (γ-(Fe,Ni))
Gneiss
Gneiss (High-grade metamorphic rock)
Ferruginous Quartz
Iron-stained Quartz (SiO2 with Fe2O3 impurities)
Chrysocolla and Azurite on Matrix
Hydrated copper silicate (Cu,Al)2H2Si2O5(OH)4 (Chrysocolla) and Copper carbonate hydroxide Cu3(CO3)2(OH)2 (Azurite)
Silver (Jewelry Specimen)
Native Silver (Ag)
Azurite with Malachite and Limonite
Azurite Cu3(CO3)2(OH)2 / Malachite Cu2CO3(OH)2
Quartzite with Iron inclusions
Metamorphosed Sandstone (SiO2 with Fe2O3)
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Limonite
Limonite (Hydrous iron oxides, FeO(OH)·nH2O)
Gold
Native Gold (Au)
Silver (Sterling Silver Jewelry)
Argentum (Ag) mixed with Copper (Cu)
Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
Quartz Druzy on Matrix (with Copper Mineralization)
Silicon Dioxide (SiO2) with Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·n H2O)
Malachite
Copper Carbonate Hydroxide [Cu2CO3(OH)2]
Quartz with Iron Staining
Silicon Dioxide (SiO2) with Hematite inclusions
Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Green Apophyllite
Fluorapophyllite-(K), KCa4(Si8O20)(F,OH)·8H2O
Carnelian
Carnelian (a variety of Chalcedony, SiO2)
Fluorite (often referred to casually as 'Fluorspar' in industrial contexts)
Fluorite (CaF2)
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Rutilated Quartz
Quartz (SiO2) with Rutile (TiO2) inclusions
Aquamarine
Beryl (Be₃Al₂Si₆O₁₈), specifically a blue or cyan variety
Sandstone
Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)
Gneiss
Gneissic Metamorphic Rock
Iron Slag
Anthropogenic Vitreous Silicate (Byproduct of Smelting)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Abalone Shell (Mother of Pearl)
Aragonite (Biogenic Calcium Carbonate, CaCO3)
Pearl
Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3
Green Aventurine (Quartzite)
Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
Dalmatian Jasper (or Dalmatian Stone)
Dalmatian Stone (A peralkaline felsite composed of feldspar, quartz, and sodic amphibole)
Diamond (in a cluster setting)
Crystallized Carbon (C)
Greenstone
Metamorphosed Mafic Igneous Rock
Diabase (also known as Dolerite)
Diabase / Dolerite