Banded Calcite
Calcite (Calcium Carbonate, CaCO3)
mineral
Category
Mineral Description (Anthropogenic Material)
Browse mineral description (anthropogenic material) specimens identified by the Rock Identifier community.
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Sandstone (specifically Arkose or Ferruginous Sandstone)
Sandstone (SiO2 predominant)
sedimentary
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 cement)
sedimentary
Sandstone
Arenite (primarily Quartz Arenite)
sedimentary
Granodiorite
Granodiorite
igneous
Tumbled red jasper with a quartz vein
Jasper (microcrystalline quartz, SiO₂), likely crossed by milky quartz
metamorphic
Sandstone with Quarzite clasts
Arenite (SiO2 based)
sedimentary
Sandstone
Arenite (Clastic Sedimentary Rock)
sedimentary
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Biotite (Black Mica)
Biotite - K(Mg,Fe)3(AlSi3O10)(F,OH)2
mineral
Coal (Anthracite / Bituminous)
Organic Sedimentary Rock (Carbon-based)
sedimentary
Weathered sandstone or iron-stained siltstone
Quartz-rich clastic sedimentary rock, likely ferruginous sandstone
sedimentary
Actinolite (likely fibrous amphibole)
Actinolite, Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂; possibly an actinolite–tremolite specimen
mineral
Porphyritic granite (likely weathered granitic rock)
Granite; chiefly quartz, alkali feldspar, plagioclase, and biotite/hornblende
igneous
Schist
Mica Schist
metamorphic
Terracotta (Man-made ceramic brick fragment)
Baked clay / High-iron ceramic (Silicate-based ceramic)
Anthropogenic material (Man-made sedimentary mimic)
Sandstone
Arenite (SiO2 based)
sedimentary
Pyrite
Iron Disulfide (FeS2)
mineral
Biotite Schist
Biotite-rich Schist
metamorphic
Granite Boulder
Felsic Intrusive Igneous Rock
igneous
Tumbled orange calcite
Calcite (calcium carbonate, CaCO₃)
mineral
Iron-rich jasper (red jasper/ironstone)
Microcrystalline quartz (SiO₂) colored by hematite and goethite
mineral
Quartz-rich translucent pebble, possibly iron-stained quartz or chalcedony
Quartz (SiO₂), potentially microcrystalline quartz (chalcedony)
mineral
Weathered quartz-rich rock, likely milky quartz or quartzite
Quartz (SiO₂), possibly quartzite with iron-oxide staining
mineral
Milky rose quartz
Quartz, silicon dioxide (SiO₂), pink variety likely colored by trace elements or microscopic inclusions
mineral
Rose Quartz
SiO2 (Silicon Dioxide)
mineral
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
mineral
Milky Quartz (Water-worn Pebble)
Silicon Dioxide (SiO2)
mineral
Pyrite in Quartz
Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)
mineral
Peridot (Olivine)
Magnesium Iron Silicate (Mg,Fe)2SiO4
mineral
Milky Quartz
Crystalline Silicon Dioxide (SiO2)
mineral
Olivine
(Mg,Fe)2SiO4 (Magnesium Iron Silicate)
mineral
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions (K(Al,Cr)2AlSi3O10(OH)2)
mineral
Milky Quartz with inclusions
Silicon Dioxide (SiO2)
mineral
Calcite
Calcium Carbonate (CaCO3)
mineral
Pyrite
Iron disulfide (FeS2)
mineral
Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Agate
Agate (Silicon Dioxide, SiO2)
mineral
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
Quartz (specifically Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
mineral
Likely dark rounded pebbles
Indeterminate; possibly basalt or a dark mafic mineral such as hornblende/biotite
mineral