Rock Identifier

Category

Metamorphic (Altered Igneous Rock)

Browse metamorphic (altered igneous rock) specimens identified by the Rock Identifier community.

Anthracite Coal (Anthracite (Carbon-rich metamorphic rock)) — metamorphic

Anthracite Coal

Anthracite (Carbon-rich metamorphic rock)

Anthracite Coal (Low-grade metamorphic carbonaceous rock) — metamorphic

Anthracite Coal

Low-grade metamorphic carbonaceous rock

Gneiss (Gneiss (High-grade metamorphic rock)) — metamorphic

Gneiss

Gneiss (High-grade metamorphic rock)

Gneiss (Gneiss (High-grade Metamorphic Rock)) — metamorphic

Gneiss

Gneiss (High-grade Metamorphic Rock)

Emerald in Matrix (Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities) — mineral

Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Green Quartzite (River Stone) (Metamorphic Quartz (SiO2) with inclusions (typically Fuchsite or Chlorite)) — metamorphic

Green Quartzite (River Stone)

Metamorphic Quartz (SiO2) with inclusions (typically Fuchsite or Chlorite)

Quartzite River Rock (Quartzite (primarily SiO2)) — metamorphic

Quartzite River Rock

Quartzite (primarily SiO2)

Quartzite pebble (Metamorphic Quartzite (primarily SiO2)) — metamorphic

Quartzite pebble

Metamorphic Quartzite (primarily SiO2)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Basalt (Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)) — igneous

Basalt

Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)

Tourmaline (likely Schorl) (Tourmaline Group Mineral (e.g., Schorl for black varieties); (Na,Ca)(Li,Mg,Fe,Mn,Al)3Al6(BO3)3Si6O18(OH)4) — Mineral

Tourmaline (likely Schorl)

Tourmaline Group Mineral (e.g., Schorl for black varieties); (Na,Ca)(Li,Mg,Fe,Mn,Al)3Al6(BO3)3Si6O18(OH)4

Rough Emerald in Matrix (Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium) — mineral

Rough Emerald in Matrix

Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium

Serpentinite (often containing Jadeite/Nephrite) (Antigorite-rich Serpentine Rock, (Mg, Fe)3Si2O5(OH)4) — metamorphic

Serpentinite (often containing Jadeite/Nephrite)

Antigorite-rich Serpentine Rock, (Mg, Fe)3Si2O5(OH)4

Basalt (Basalt) — igneous

Basalt

Basalt

Garnet Schist or Garnet-bearing Quartzite (Metamorphic rock containing Almandine Garnet (Fe3Al2(SiO4)3) and Quartz (SiO2)) — metamorphic

Garnet Schist or Garnet-bearing Quartzite

Metamorphic rock containing Almandine Garnet (Fe3Al2(SiO4)3) and Quartz (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite (Metamorphic rock predominantly composed of Quartz (SiO2)) — metamorphic

Quartzite

Metamorphic rock predominantly composed of Quartz (SiO2)

Serpentinite (Serpentinite (complex silicate minerals including lizardite, chrysotile, and antigorite)) — metamorphic

Serpentinite

Serpentinite (complex silicate minerals including lizardite, chrysotile, and antigorite)

Schist (Mica Schist (primarily composed of quartz, feldspar, and mica)) — metamorphic

Schist

Mica Schist (primarily composed of quartz, feldspar, and mica)

Quartzite (River Pebble) (Quartzite (composed primarily of Silica, SiO2)) — metamorphic

Quartzite (River Pebble)

Quartzite (composed primarily of Silica, SiO2)

Mica Schist (Mica Schist (Quartz-Biotit-Muscovite Schist)) — metamorphic

Mica Schist

Mica Schist (Quartz-Biotit-Muscovite Schist)

Unakite (Unakite (Epidotized Granite)) — metamorphic

Unakite

Unakite (Epidotized Granite)

Quartzite (Iron-stained) (Quartzite (SiO2 with Iron oxide inclusions)) — metamorphic

Quartzite (Iron-stained)

Quartzite (SiO2 with Iron oxide inclusions)

Labradorite (Labradorite (Ca, Na)(Al, Si)4O8) — mineral

Labradorite

Labradorite (Ca, Na)(Al, Si)4O8

Serpentine (Lizardite) (Serpentine subgroup, Mg3Si2O5(OH)4) — metamorphic

Serpentine (Lizardite)

Serpentine subgroup, Mg3Si2O5(OH)4

Quartzite with Chlorite/Epidote (Metamorphosed Quartzite (SiO2)) — metamorphic

Quartzite with Chlorite/Epidote

Metamorphosed Quartzite (SiO2)

Basalt (Basalt (Igneous Volcanic)) — igneous

Basalt

Basalt (Igneous Volcanic)

Basalt (Mafic Igneous Basalt) — igneous

Basalt

Mafic Igneous Basalt

Serpentine (Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4) — metamorphic

Serpentine

Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4

Marble (Recrystallized Carbonate Rock (CaCO3)) — metamorphic

Marble

Recrystallized Carbonate Rock (CaCO3)

Calcite (Calcite (Calcium Carbonate, CaCO3)) — mineral

Calcite

Calcite (Calcium Carbonate, CaCO3)

Granite (Phaneritic Felsic Igneous Rock) — igneous

Granite

Phaneritic Felsic Igneous Rock

Serpentinite (Serpentinite (group of minerals: Antigorite, Lizardite, Chrysotile)) — metamorphic

Serpentinite

Serpentinite (group of minerals: Antigorite, Lizardite, Chrysotile)

Tiger's Eye (Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)) — metamorphic

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)

Tiger's Eye (Pseudomorph of Quartz after Crocidolite (SiO2)) — mineral

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Muscovite Mica (Muscovite (KAl2(AlSi3O10)(OH)2)) — mineral

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Green Aventurine (Silicon Dioxide with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)) — mineral

Green Aventurine

Silicon Dioxide with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)

Black Tourmaline (Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)) — mineral

Black Tourmaline

Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)

Basalt (River Pebble) (Mafic volcanic rock (rich in magnesium and iron)) — igneous

Basalt (River Pebble)

Mafic volcanic rock (rich in magnesium and iron)

Granite Pebble (Granite (composition of Quartz, Alkali Feldspar, and Plagioclase)) — igneous

Granite Pebble

Granite (composition of Quartz, Alkali Feldspar, and Plagioclase)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Garnet (Almandine variety) (Almandine Garnet (Fe3Al2(SiO4)3)) — mineral

Garnet (Almandine variety)

Almandine Garnet (Fe3Al2(SiO4)3)