Chert Nodule (with Ironstone Cortex)
Microcrystalline Silica (SiO2)
Category
Browse mineral, possibly rock fragment containing a mineral specimens identified by the Rock Identifier community.
Chert Nodule (with Ironstone Cortex)
Microcrystalline Silica (SiO2)
Rough Tanzanite
Zoisite (Ca2Al3(SiO4)3(OH))
Garnet Schist
Garnet-bearing Mica Schist (variety of compositions, often Al2SiO5 with X3Y2(SiO4)3)
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 cement)
Anthracite Coal
Anthracite (Carbon-rich metamorphic rock)
Bituminous Coal
Organic Sedimentary Rock (Carbon-based)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Vesicular Basalt with Quartz/Chalcedony
Vesicular Basalt (primarily Plagioclase, Pyroxene, and Olivine with SiO2 infill)
Quartzite with Iron Mineral Banding
Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3) staining
Mica Schist
Mica Schist (predominantly Muscovite or Biotite sheet silicates)
Sodalite
Sodalite (Sodium Aluminum Silicate Chloride), Na8(Al6Si6O24)Cl2
Pebble (Likely Basalt or Siltstone)
Clastic sedimentary rock or mafic volcanic rock
Milky Quartz in Matrix
Silicon Dioxide (SiO2)
Hematite
Hematite (Fe2O3)
Clear Quartz Cluster
Silicon Dioxide (SiO2)
Epidote (Unakite variety)
Epidosite (Metasomatic rock containing Ca2(Al,Fe)3(SiO4)3(OH))
Ferruginous Sandstone (Red Sandstone)
Arenite with Hematite/Limonite cement
Granite
Phaneritic Felsic Igneous Rock (composed of SiO2, KAlSi3O8, NaAlSi3O8)
Gneiss
Gneiss
Petrified Wood
Silicified Wood (SiO2)
Agate Nodule / Weathered Chert
SiO2 (Silicon Dioxide - Microcrystalline Quartz)
Granite
Granite (Mainly Quartz SiO2 and Feldspar KAlSi3O8)
Schist (Micaceous Schist)
Micaceous schist (Mainly Muscovite/Biotite mixed with Quartz)
Amethyst
Silicon Dioxide with iron impurities (SiO2)
Granite (with alteration)
Granite (Felsic intrusive igneous rock)
Thunderegg (specifically a Jasper/Agate-filled Geode nodule)
Silicon Dioxide (SiO2) within Rhyolitic Matrix
Blue Lace Agate
Chalcedony (SiO2) with trace inclusions
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
Turquoise
Turquoise (Hydrated phosphate of copper and aluminium) CuAl6(PO4)4(OH)8·4H2O
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Tumbled Stones (various)
Mixed Silica-based Minerals (primarily Quartz and Chalcedony)
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
Quartz Pebble
Silicon Dioxide (SiO2)
Chert / Flint
Cryptocrystalline quartz (SiO2)
Amber
Fossilized Tree Resin (Amorphous Hydrocarbon)
Obsidian
Obsidian (principally SiO2 with MgO and Fe3O4)
Glaucophane Schist (Blueschist)
Blueschist (Glaucophane-bearing schist)
Granite
Granite (Mainly Quartz, Feldspar, and Mica/Amphibole)
Red Jasper (Polished)
Silicon Dioxide (SiO2) with Hematite inclusions
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
Ferruginous Quartz
Quartz (Silicon Dioxide) with Iron Inclusion, SiO2
Petrified Wood
Silicified wood (Quartz, SiO2)