Rock Identifier

Category

Metamorphic (Altered Igneous Rock)

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

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Milky Quartz Pebble (Crystalline Silicon Dioxide (SiO2)) — mineral

Milky Quartz Pebble

Crystalline Silicon Dioxide (SiO2)

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

Green Aventurine

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

Quartzite Cobble (Metamorphosed Quartz Sandstone (SiO2)) — metamorphic

Quartzite Cobble

Metamorphosed Quartz Sandstone (SiO2)

Red Garnet (likely Almandine or Pyrope) (Garnet group: X3Y2(SiO4)3 (e.g., Almandine: Fe3Al2Si3O12)) — mineral

Red Garnet (likely Almandine or Pyrope)

Garnet group: X3Y2(SiO4)3 (e.g., Almandine: Fe3Al2Si3O12)

Serpentinite (Serpentinite (complex silicate minerals including lizardite, chrysotile, and antigorite: (Mg,Fe)3Si2O5(OH)4)) — metamorphic

Serpentinite

Serpentinite (complex silicate minerals including lizardite, chrysotile, and antigorite: (Mg,Fe)3Si2O5(OH)4)

Basalt (Aphanitic Mafic Igneous Rock) — igneous

Basalt

Aphanitic Mafic Igneous Rock

Granite Pebble (Granite (composed primarily of Quartz, Feldspar, and Mica)) — igneous

Granite Pebble

Granite (composed primarily of Quartz, Feldspar, and Mica)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite with inclusions (Metamorphic Rock (Mainly SiO2)) — metamorphic

Quartzite with inclusions

Metamorphic Rock (Mainly SiO2)

Granite Pebbles (Granite (composed primarily of Quartz SiO2, Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8), and Mica)) — igneous

Granite Pebbles

Granite (composed primarily of Quartz SiO2, Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8), and Mica)

Sandstone (Micaceous) (Clastic Sedimentary Rock (primarily SiO2 with Mica)) — sedimentary

Sandstone (Micaceous)

Clastic Sedimentary Rock (primarily SiO2 with Mica)

Slickenside (Tectonic Fault Scarp Surface) — metamorphic

Slickenside

Tectonic Fault Scarp Surface

Quartz (Quartz (SiO2 - Silicon Dioxide)) — Mineral

Quartz

Quartz (SiO2 - Silicon Dioxide)

Quartzite (Quartzite) — Metamorphic

Quartzite

Quartzite

Blue Apatite (Fluorapatite (Ca5(PO4)3F)) — mineral

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Biotite on Matrix (Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)) — mineral

Biotite on Matrix

Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Granite or Porphyritic Igneous Rock (weathered) (Granitoid) — Igneous

Granite or Porphyritic Igneous Rock (weathered)

Granitoid

Travertine (Terrestrial Sedimentary Limestone (CaCO3)) — sedimentary

Travertine

Terrestrial Sedimentary Limestone (CaCO3)

Quartz Vein in Host Rock (Silicon Dioxide (SiO2) within Sedimentary/Metamorphic Matrix) — Metamorphic or Igneous (context dependent)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Sedimentary/Metamorphic Matrix

Metamorphic or Igneous (context dependent)

Gneiss (likely) (Gneiss) — Metamorphic

Gneiss (likely)

Gneiss

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock

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

Quartzite River Rock

Quartzite (primarily SiO2)

Unakite (Epidotized Granite) — metamorphic

Unakite

Epidotized Granite

Quartzite with Hematite staining (Quartzite (SiO2) with iron oxide inclusions) — metamorphic

Quartzite with Hematite staining

Quartzite (SiO2) with iron oxide inclusions

Quartzite (River Pebble) (Meta-quartzite (composed primarily of SiO2)) — metamorphic

Quartzite (River Pebble)

Meta-quartzite (composed primarily of SiO2)

Quartz Vein in Pelite (Metamorphic Rock) (Hydrothermal Quartz Veining in Metasedimentary Rock (SiO2)) — metamorphic

Quartz Vein in Pelite (Metamorphic Rock)

Hydrothermal Quartz Veining in Metasedimentary Rock (SiO2)

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

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

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

Serpentinite

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

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

Serpentine (Serpentinite)

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

Granodiorite with Quartz Veining (Granodiorite (containing Plagioclase Feldspar, Quartz, and Biotite/Hornblende) with Quartz (SiO2) veins) — igneous

Granodiorite with Quartz Veining

Granodiorite (containing Plagioclase Feldspar, Quartz, and Biotite/Hornblende) with Quartz (SiO2) veins

Anthracite Coal (Anthracite (Carbon C)) — metamorphic

Anthracite Coal

Anthracite (Carbon C)

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

Calcite

Calcite (CaCO₃, Calcium Carbonate)

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

Labradorite

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

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

Labradorite

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

River Rock (likely Quartzite or Chert) (Quartzite (primarily SiO2)) — metamorphic

River Rock (likely Quartzite or Chert)

Quartzite (primarily SiO2)

Shale (possibly Carbonaceous or Oil Shale) (Argillaceous Sedimentary Rock) — sedimentary

Shale (possibly Carbonaceous or Oil Shale)

Argillaceous Sedimentary Rock

Quartz (likely a weathered/tumbled piece) (Quartz (SiO₂)) — Mineral

Quartz (likely a weathered/tumbled piece)

Quartz (SiO₂)

Granite (Granite (Mainly Quartz, Feldspar, and Mica)) — igneous

Granite

Granite (Mainly Quartz, Feldspar, and Mica)

Moonstone (Orthoclase (Potassium Aluminum Silicate), Formula: (K,Na)AlSi3O8) — mineral

Moonstone

Orthoclase (Potassium Aluminum Silicate), Formula: (K,Na)AlSi3O8

Granite (Granite (Felsic Plutonic Rock)) — igneous

Granite

Granite (Felsic Plutonic Rock)