Sandstone
Arenite (primarily SiO2)
Category
Browse mineral (biogenic) specimens identified by the Rock Identifier community.
Sandstone
Arenite (primarily SiO2)
Azurite and Malachite
Azurite (Cu3(CO3)2(OH)2) and Malachite (Cu2(CO3)(OH)2)
Ironstone Concretion (Iron-rich Mudstone)
Siderite / Geothite concretion (FeCO3 / FeO(OH))
Dalmatian Stone
Peralkaline Feldsphathic Igneous Rock
Yellow Jasper
Chalcedony (Silicon Dioxide with Iron inclusions), SiO2
Grey River Stone (Gneiss/Schist mix)
Foliated Metamorphic Rock (variable mineral formula)
Feldspar
KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8
Quartz Geode
Crystalline Silicon Dioxide (SiO2) within a nodule
Quartz Vein in Schist
Quartz (SiO2) in Mica Schist
Quartz Geode
Silicon Dioxide (SiO2)
Turquoise
Hydrated phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O
Turquoise
CuAl6(PO4)4(OH)8·4H2O
Red Sandstone
Arenite (primarily SiO2 with Fe2O3)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Sandstone with Iron Oxide Staining
Arenite with Limonite/Hematite alteration
Ironstone Concretion
Siderite or Hematite Concretion
Red Sandstone
Arenite (primarily Quartz, SiO2, with Iron Oxide cementing agent)
Fossilized Bone Fragment
Permineralized Vertebrate Bone (Hydrox yapatite replaced by Silica or Calcite)
Turquoise
CuAl6(PO4)4(OH)8·4H2O
Ironstone (with Limonite/Goethite)
Ferruginous Sedimentary Rock (contains Limonite FeO(OH)·nH2O and Hematite Fe2O3)
Azurite and Malachite on Matrix
Azurite: Cu3(CO3)2(OH)2; Malachite: Cu2CO3(OH)2
Dendritic Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Desert Rose (Sand Barite/Gypsum Rose)
Barium Sulfate (BaSO4) or Hydrated Calcium Sulfate (CaSO4·2H2O)
Botryoidal Goethite
Goethite (α-Fe3+O(OH))
Brown Sandstone
Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)
Sandstone (Ferruginous)
Arenite with Iron Oxide cement (SiO2 + Fe2O3)
Turquoise
CuAl6(PO4)4(OH)8·4H2O
Yellow Jade (often Serpentine or Dolomite)
Primarily Serpentine (Mg3Si2O5(OH)4) or Dolomite (CaMg(CO3)2), though the term 'yellow jade' is also sometimes applied to varieties of true nephrite or jadeite.
Desert Rose (Gypsum/Baryte)
Hydrated Calcium Sulfate (CaSO4·2H2O)
Quartz Geode with Goethite/Hematite
Silicon Dioxide (SiO2) with Iron Oxides
Fire Opal in Host Rock
Amorphous Hydrous Silica (SiO2·nH2O)
Biotite Mica
Biotite (K(Mg,Fe)3AlSi3O10(OH,F)2)
Sunstone
Oligoclase (Plagioclase Feldspar), (Na,Ca)(Si,Al)4O8
Amethyst
Silicon dioxide (SiO2) with iron impurities
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Malachite with Chrysocolla
Copper carbonate hydroxide (Cu2CO3(OH)2) and Hydrated copper silicate (Cu,Al)2H2Si2O5(OH)4·nH2O
Goethite pseudomorph after Pyrite
Goethite (FeO(OH)) pseudomorph after Pyrite (FeS2)
Smoky Quartz (Herkimer-style)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Chakra Tumbled Stone Set
Various (including Amethyst [SiO2], Sodalite [Na8(Al6Si6O24)Cl2], Green Aventurine [SiO2], Red Jasper [SiO2], etc.)