River Pebble (Gabbro or Dark Sandstone variety)
Mafic Intrusive Rock (Plagioclase Feldspar and Pyroxene)
igneous
Category
Mineral Based Alloy (Anthropogenic)
Browse mineral based alloy (anthropogenic) specimens identified by the Rock Identifier community.
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Fossilized Shark Tooth (Dermal Denticle or worn tooth fragment)
Elasmobranchii (fossil remains)
sedimentary
Limestone (specifically Grainstone or Micrite)
Calcium Carbonate (CaCO3)
sedimentary
Fossilized Gastropod Internal Mold
Steinkern (Mollusca: Gastropoda)
sedimentary
Moss Agate
SiO2 (Silicon Dioxide) with dendritic inclusions
Mineral
Mica Schist
Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3(AlSi3O10)(OH)2)
metamorphic
Granite
Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)
igneous
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Basalt Scoria
Aphanitic basaltic scoria
igneous
Basalt Gravel
Basalt
igneous
Basalt pebble
Aphanitic Mafic Volcanic Rock (Fe/Mg rich)
igneous
Basalt with Plagioclase Phenocrysts
Basalt
igneous
Granite
Granite (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Pink Granite
Phaneritic Quartz-Feldspar Plutonic Rock
igneous
Quartzite Pebble
Quartzite (SiO2)
metamorphic
Pink Granite
Granite (Phaneritic igneous rock rich in Orthoclase)
igneous
Basalt
Basalt
igneous
Granite
Granite
igneous
Basalt
Basalt (Mafic Extrusive)
igneous
Fossiliferous Limestone
Bioclastic Limestone (CaCO3)
sedimentary
Basalt (potential Glacial Erratic)
Extrusive Mafic Volcanic Rock (Basalt)
igneous
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
Basalt
Mafic volcanic rock (Basalt)
igneous
Granite
Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)
igneous
Granite
Granite (Phaneritic intrusive igneous rock)
igneous
Granite
Felsic intrusive igneous rock
igneous
Granite
Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)
igneous
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Granite
Granite (Mainly Quartz, Feldspar, and Mica)
igneous
Porphyritic Andesite
Andesite
Igneous
Porphyritic Basalt
Basalt (with plagioclase phenocrysts)
igneous
Chert (and/or River Pebble)
Microcrystalline silica (SiO2)
sedimentary
Rhyolite Porphyry
Rhyolite (High-silica volcanic rock)
igneous
Basalt with Quartz Veins
Vesicular or aphanitic Basalt with SiO2 (Quartz) intrusions
Igneous
Micaceous Rock (likely Muscovite Schist/Gneiss or a Muscovite-rich Specimen)
Predominantly Muscovite (KAl2(AlSi3O10)(F,OH)2), often found in rocks like Muscovite Schist or Muscovite Gneiss.
Metamorphic, Mineral (within a rock type)
Snowflake Obsidian
Volcanic glass (SiO2) with Cristobalite (SiO2) inclusions
igneous
River Cobble (likely Serpentinite or Greenstone)
Serpentinite / Greenschist facies rock
metamorphic
Banded Gneiss
Gneiss (Metamorphic rock of variable mineralogy, often quartz-feldspar base)
metamorphic
Biotite Schist
Biotite Schist
Metamorphic
Biotite Schist
Biotite Schist (containing K(Mg,Fe)3AlSi3O10(OH)2)
metamorphic
Precious Opal
Hydrated Silica (SiO2·nH2O)
mineraloid