Rock Identifier

Category

Metamorphic Or Igneous Alteration

Browse metamorphic or igneous alteration specimens identified by the Rock Identifier community.

Quartz / Quartzite (Silicon Dioxide (SiO2)) — mineral / metamorphic

Quartz / Quartzite

Silicon Dioxide (SiO2)

mineral / metamorphic

Schist (Mica Schist (primarily Muscovite or Biotite sheet silicates)) — metamorphic

Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

Greenschist with Quartz Veining (Greenschist (commonly containing Chlorite, Actinolite, and Epidote)) — metamorphic

Greenschist with Quartz Veining

Greenschist (commonly containing Chlorite, Actinolite, and Epidote)

Gneiss (Gneiss) — metamorphic

Gneiss

Gneiss

Gneiss (Gneiss) — metamorphic

Gneiss

Gneiss

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

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Greenstone with Quartz Veining (Epidiorite or Metabasalt with SiO2 (Quartz) veins) — metamorphic

Greenstone with Quartz Veining

Epidiorite or Metabasalt with SiO2 (Quartz) veins

Greenstone (Protolith of basalt, diabase, or gabbro; often contains minerals like chlorite, actinolite, and epidote) — metamorphic

Greenstone

Protolith of basalt, diabase, or gabbro; often contains minerals like chlorite, actinolite, and epidote

Biotite Schist (Biotite-rich Schist (K(Mg,Fe)3AlSi3O10(OH,F)2)) — metamorphic

Biotite Schist

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

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

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Greenschist (Chlorite Schist) (Greenschist (Metamorphic rock dominated by chlorite, actinolite, and epidote)) — metamorphic

Greenschist (Chlorite Schist)

Greenschist (Metamorphic rock dominated by chlorite, actinolite, and epidote)

Quartz (Quartz (SiO₂)) — Mineral

Quartz

Quartz (SiO₂)

Gneiss (High-grade Metamorphic Gneiss) — metamorphic

Gneiss

High-grade Metamorphic Gneiss

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

Gneiss (High-grade Metamorphic Rock)

Gneiss (Metamorphic silicate rock)

Fluorite with Quartz coating (Calcium Fluoride (CaF2) with Silicon Dioxide (SiO2)) — mineral

Fluorite with Quartz coating

Calcium Fluoride (CaF2) with Silicon Dioxide (SiO2)

Quartz Pebble (Quartz (Silicon Dioxide - SiO2)) — mineral

Quartz Pebble

Quartz (Silicon Dioxide - SiO2)

Biotite (Mica) (Biotite group (K(Mg,Fe)3AlSi3O10(F,OH)2)) — mineral

Biotite (Mica)

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

Quartz Pebble (Silicon Dioxide (SiO2)) — Mineral (occurring as a rolled clast)

Quartz Pebble

Silicon Dioxide (SiO2)

Mineral (occurring as a rolled clast)

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

Gneiss

Gneiss (High-grade regional metamorphic rock)

Gneiss (Banded Gneiss) (Gneiss) — metamorphic

Gneiss (Banded Gneiss)

Gneiss

Gneiss (Gneiss) — metamorphic

Gneiss

Gneiss

Gneiss (with Quartz-Feldspar vein) (Gneiss (high-grade metamorphic rock) containing Quartz (SiO2) and Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8)) — metamorphic

Gneiss (with Quartz-Feldspar vein)

Gneiss (high-grade metamorphic rock) containing Quartz (SiO2) and Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8)

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

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

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

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Quartz in Matrix (possibly with Biotite or Hornblende) (Quartz (Silicon Dioxide, SiO2) in Granitic Matrix) — igneous

Quartz in Matrix (possibly with Biotite or Hornblende)

Quartz (Silicon Dioxide, SiO2) in Granitic Matrix

Blue Sapphire (Corundum (Al2O3)) — mineral

Blue Sapphire

Corundum (Al2O3)

Banded Gneiss (Gneiss (Metamorphic rock composed of feldspar, quartz, and mica)) — metamorphic

Banded Gneiss

Gneiss (Metamorphic rock composed of feldspar, quartz, and mica)

Gneiss (Gneiss) — metamorphic

Gneiss

Gneiss

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

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

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

Granitic Gneiss

Gneiss (High-grade Metamorphic Rock)

Schist (Mica Schist (Variable chemistry, often rich in muscovite and biotite)) — metamorphic

Schist

Mica Schist (Variable chemistry, often rich in muscovite and biotite)

Gneiss (High-Grade Metamorphic Rock) (Gneiss (primarily composed of Quartz, Feldspar, and Mica/Amphiboles)) — metamorphic

Gneiss (High-Grade Metamorphic Rock)

Gneiss (primarily composed of Quartz, Feldspar, and Mica/Amphiboles)

Gneiss (Gneiss) — metamorphic

Gneiss

Gneiss

Nephrite Jade (Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)) — Metamorphic

Nephrite Jade

Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)

Gneiss (specifically a Banded Gneiss cobble) (Gneiss (composed mainly of Quartz, Feldspar, and Biotite/Amphibole)) — metamorphic

Gneiss (specifically a Banded Gneiss cobble)

Gneiss (composed mainly of Quartz, Feldspar, and Biotite/Amphibole)

Quartz with Iron Stains (Quartz (SiO2) with iron oxide/hydroxide staining) — Mineral

Quartz with Iron Stains

Quartz (SiO2) with iron oxide/hydroxide staining

Black Tourmaline (Schorl) (Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)) — mineral

Black Tourmaline (Schorl)

Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)

Red Feldspar (Orthoclase) (Orthoclase Feldspar (KAlSi3O8)) — mineral

Red Feldspar (Orthoclase)

Orthoclase Feldspar (KAlSi3O8)

Citrine Quartz (Silicon Dioxide (SiO2) with iron impurities) — mineral

Citrine Quartz

Silicon Dioxide (SiO2) with iron impurities

Milky Quartz with Iron Inclusions (Silicon Dioxide (SiO2)) — mineral

Milky Quartz with Iron Inclusions

Silicon Dioxide (SiO2)

Pyrite (Fools Gold) (Iron Sulfide (FeS2)) — mineral

Pyrite (Fools Gold)

Iron Sulfide (FeS2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)