Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Category
Mineral (Tectosilicate)
Browse mineral (tectosilicate) specimens identified by the Rock Identifier community.
Green Aventurine
Aventurine Quartz (SiO2 + Fuchsite mica)
Mineral
Sandstone
Sandstone (lithified quartz arenite, arkose, graywacke, etc. depending on composition)
Sedimentary Rock
Magnetite (Iron Ore)
Magnetite (Fe3O4)
mineral
Pink Granite
Felsic Plutonic Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)
Igneous
Hematite Beads
Hematite (Fe2O3)
Mineral
Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Schist
Mica Schist (primarily consisting of muscovite KAl2(AlSi3O10)(OH)2 or biotite K(Mg,Fe)3(AlSi3O10)(OH)2)
metamorphic
Gneiss
Gneiss
metamorphic
Schist
Mica Schist
metamorphic
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
mineral
Limonite (Iron Ore)
Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)
Mineral
Quartz (Riverstone / Cobble)
Silicon Dioxide (SiO2)
mineral
Aventurine (likely Green Aventurine)
Quartz (SiO2) with included minerals (Fuchsite or Chlorite for green color)
Mineral
Chakra Stone Bracelet (mixed gemstones)
Multi-mineral/Gemstone assembly (primarily Quartz variety beads)
mineral
Gneiss
Gneiss
metamorphic
Fossilized Shark Teeth
Carcharhiniformes or Lamniformes species (common mineral: Fluorapatite/Ca5(PO4)3F)
sedimentary (fossilized organic matter)
Serpentinite (often containing Jadeite/Nephrite)
Antigorite-rich Serpentine Rock, (Mg, Fe)3Si2O5(OH)4
metamorphic
Granite
Phaneritic Felsic Igneous Rock
igneous
Chert Pebble (Jasper/Quartz variety)
Microcrystalline Quartz (SiO2)
sedimentary
Basalt (Amygdaloidal)
Amygdaloidal Basalt
igneous
Schist
Mica Schist
metamorphic
Fluorite in Matrix
Fluorite (CaF2) within a host rock matrix
Mineral
Moonstone (bead form)
Potassium Aluminum Silicate (KAlSi3O8) - a variety of Orthoclase Feldspar
Mineral
Sandstone (with Liesegang rings or joints)
Clastic Sedimentary Rock (primarily Quartz with Iron Oxide cement)
sedimentary
Vesicular Basalt (Amygdaloidal)
Amygdaloidal Basalt (Mafic volcanic rock)
igneous
Rugose Coral (Horn Coral)
Order Rugosa (extinct fossilized coral)
sedimentary
Piddock bored rock (likely Mudstone or Shale)
Ichnofossil (Gastrochaenolites borings) in Fine-grained Sedimentary Rock
sedimentary
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Banded Gneiss
Gneiss (pronounced "nice")
metamorphic
Selenite (Satin Spar)
Gypsum (CaSO4·2H2O)
mineral
Pink Granite
Phaneritic Felsic Igneous Rock
igneous
Greenschist (Greenstone)
Chlorite schist (primarily Chlorite-Epidote-Actinolite-Albite)
metamorphic
Chalcedony or Chert/Jasper with secondary mineral staining
SiO2 (for chalcedony/quartz) with possible secondary copper minerals (e.g., CuSiO3·nH2O for chrysocolla, Cu2(CO3)(OH)2 for malachite) or iron oxides/hydroxides.
Mineral, potentially a rock with chalcedony/jasper.
Granite / Gneiss Complex
Felsic Plutonic Rock (Granite) or High-grade Metamorphic Rock (Gneiss)
igneous/metamorphic
Sandstone
Arenite (SiO2 predominantly)
sedimentary
Hematite
Iron(III) oxide (Fe2O3)
mineral
Pink Satin Spar (Satin Spar Selenite Dyed)
Gypsum (CaSO4·2H2O)
mineral
Moonstone (Feldspar)
Orthoclase (KAlSi3O8) or Albite (NaAlSi3O8)
mineral
Basalt
Basalt (extrusive igneous rock)
Igneous
Rutilated Quartz
Silicon Dioxide with Titanium Dioxide (SiO2 with TiO2 inclusions)
mineral
Peach Aventurine
Quartz variety (SiO2 + Hematite/Goethite inclusions)
mineral