Schist
Mica Schist
Category
Browse mineral, possibly rock fragment containing a mineral specimens identified by the Rock Identifier community.
Schist
Mica Schist
Greenstone (Epidote/Chlorite Rich Rock)
Metabasalt (often contains Epidote Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH))
Ironstone Concretion
Siderite or Ferruginous Concretion (FeCO3 or Iron Oxides)
Basalt
Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)
Milky Quartz
Silicon Dioxide (SiO2)
Schist
Mica Schist (Medium-grade metamorphic rock)
Tumbled Obsidian (possibly Mahogany Obsidian variant)
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
Limestone
Calcareous Sedimentary Rock (CaCO3)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Granite
Phaneritic Granitoid (Primary minerals: Quartz SiO2, Feldspar KAlSi3O8, and Biotite/Mica)
Rough Quartz in Pegmatite Matrix
Quartz (Silicon Dioxide - SiO2) in Granitic Pegmatite
Smoky Quartz
Silicon Dioxide (SiO2)
Gneiss (with Quartz and Biotite Mica)
Gneiss
Quartz Vein with Iron Staining
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Arenite with Iron Oxide (Fe2O3) cement
Garden Quartz
Silicon Dioxide (SiO2) with various inclusions
Porphyritic Andesite
Andesite (porphyritic variety)
Serpentinite
Serpentinite (composed primarily of Serpentine minerals: Mg3Si2O5(OH)4)
Chert (Jasper)
Microcrystalline Quartz (SiO2) with iron oxide impurities
Basalt (Weathered)
Extrusive mafic volcanic rock
Basalt with Olivine Phenocrysts
Porphyritic Basalt (Mineral formula of Olivine: (Mg,Fe)2SiO4)
Tufa
Calcareous Tufa (CaCO3)
Quartz Geode
Silicon Dioxide (SiO2) in Geode form
Serpentine Schist with Quartz Vein
Serpentine Schist (a type of Metamorphic rock). The white band is likely Quartz (SiO2).
Coquina
Biogenic Limestone (Calcium Carbonate - CaCO3)
Serpentine (Serpentinite)
Serpentinite (complex silicate group including lizardite, chrysotile, and antigorite)
Gneiss
Gneiss
Coral Fossil (Petrified Coral)
Scleractinia (Order) - Calcified Fossil Skeleton (CaCO3)
Aquamarine
Aquamarine (Beryl variety) - Be3Al2(Si6O18)
Granite
Phaneritic Intrusive Igneous Rock (composed of Quartz, Feldspar, and Mica)
Amber
Succinite (C10H16O)
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz (Tumbled)
Silicon Dioxide (SiO2)
Coal (Anthracite)
Anthracite (Carbon-based organic sedimentary/metamorphic rock)
Shale (or Mudstone)
Siltstone/Argillite (composed mainly of clay and silt-sized particles)
Sodalite
Sodalite [Na8(Al6Si6O24)Cl2]
Agate (specifically, multi-colored or pastel-dyed agate)
Silicon dioxide (SiO2) - specifically, a cryptocrystalline variety of quartz known as Chalcedony, with banding classified as Agate. (If it were Fluorite, the chemical formula would be Calcium Fluoride - CaF2).
Clear Quartz (Rock Crystal Fragments)
Silicon Dioxide (SiO2)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Smoky Quartz
Silicon Dioxide (SiO2)
Agate (Geode nodule fragment)
Chalcedony (cryptocrystalline variety of Quartz), SiO2