Anthracite Coal
Anthracite (Carbon C)
metamorphic
Category
Mineral And Metamorphic Rock
Browse mineral and metamorphic rock specimens identified by the Rock Identifier community.
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Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
gemstone
Amethyst Quartz
Silicon Dioxide (SiO2)
mineral
Quartzite Pebble (River Rock)
Metamorphic Quartzite (SiO2)
metamorphic
Quartzite Pebble
Metamorphic Quartzite (SiO2)
metamorphic
Banded Gneiss
Gneiss (Metamorphic high-grade, predominantly SiO2, Al2O3, K2O, Na2O)
metamorphic
Nuummite
Nuummite (Orthoamphibole rock / Anthophyllite-Gedrite blend)
metamorphic
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Tumbled milky quartz
Quartz (silicon dioxide, SiO₂)
mineral
Tiger's Eye
SiO2 (Silicon Dioxide with inclusions of Goethite/Limonite)
Metamorphic
Gneiss (Granite Gneiss)
Gneiss
metamorphic
Gneiss
Gneiss
metamorphic
Quartz (Milky or Clear variety)
Silicon Dioxide (SiO2)
mineral
Quartzite (specifically an iron-stained or Carnelian-colored variety)
Silicon Dioxide (SiO2) with iron oxide inclusions
metamorphic
River Rock (likely Quartzite or Chert)
Quartzite (primarily SiO2)
metamorphic
Gneiss (with Quartz and Biotite Mica)
Gneiss
metamorphic
Unakite
Unakitized granodiorite / Quartz-Epidote-Feldspar rock
metamorphic
Blue Quartzite
Quartzite (primarily SiO2 with inclusions)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Slate
Foliated Metamorphic Rock (primarily composed of Muscovite, Chlorite, and Quartz)
metamorphic
Slate
Foliated Metamorphic Rock (primarily composed of quartz, illite, chlorite, and micas)
metamorphic
Waterworn greenstone pebble
Likely serpentinite or chlorite-rich metamorphic rock; exact identification requires testing
metamorphic
Unakite
Epidotized Granite
metamorphic
Greenstone (Greenstone River Pebble)
Greenschist (metamorphosed mafic igneous rock)
metamorphic
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Unakite
Unakite (altered granite)
metamorphic
Pyrite-bearing rock (iron pyrite)
Pyrite, FeS₂, likely disseminated or massive in a host rock
mineral
Smoky Quartz (with possible Feldspar inclusions)
Silicon Dioxide (SiO2)
mineral
Quartz (Milky or Clear Quartz fragment)
Silicon Dioxide (SiO2)
mineral
Quartzite with inclusions
Metamorphosed Quartz-rich Rock (SiO2)
metamorphic
Quartzite / Sandstone / Chert Mix
Silicon Dioxide (SiO2)
sedimentary and metamorphic
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Quartz-rich metamorphic fragment (likely mica schist)
Mica schist, probably muscovite–quartz schist
metamorphic
Quartzite
Quartzite (SiO2)
metamorphic
Rough Dark Green Sapphire
Corundum (Al2O3)
mineral
Basalt cobble
Basalt; predominantly plagioclase, clinopyroxene, and often olivine or iron-titanium oxides
igneous
Weathered iron-rich rock, possibly limonite/goethite
Limonite (hydrated iron oxides; commonly goethite, FeO(OH), mixed with hematite)
mineral
Quartzite with inclusions
Metamorphosed quartz sandstone
metamorphic
Slate
Slate (foliated metamorphic rock rich in quartz, sericite, and chlorite)
metamorphic
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Mica Schist
Mica Schist (predominantly Muscovite/Biotite)
metamorphic
Granitic Gneiss
Gneiss (Polymetamorphic Granitic Gneiss)
metamorphic