Rock Identifier

Category

Metamorphic Or Igneous Alteration

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

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

Biotite (Black Mica)

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

Beryl (Emerald Variety) (Beryllium aluminum silicate (Be3Al2(SiO3)6) with chromium/vanadium traces) — mineral

Beryl (Emerald Variety)

Beryllium aluminum silicate (Be3Al2(SiO3)6) with chromium/vanadium traces

Black Spinel (Magnesium Aluminum Oxide (MgAl2O4)) — mineral

Black Spinel

Magnesium Aluminum Oxide (MgAl2O4)

Eclogite (Eclogite (Omphacite-Garnet rock)) — metamorphic

Eclogite

Eclogite (Omphacite-Garnet rock)

Tanzanite (Blue Zoisite (Ca2Al3(SiO4)(Si2O7)O(OH))) — mineral

Tanzanite

Blue Zoisite (Ca2Al3(SiO4)(Si2O7)O(OH))

Greenschist (Greenstone River Pebble) (Greenschist (Chlorite Schist)) — metamorphic

Greenschist (Greenstone River Pebble)

Greenschist (Chlorite Schist)

Amphibolite (specifically Hornblende Schist/Gneiss) (Amphibole-rich Metamorphic Rock) — metamorphic

Amphibolite (specifically Hornblende Schist/Gneiss)

Amphibole-rich Metamorphic Rock

Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment) (Quartz (SiO₂)) — Mineral

Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)

Quartz (SiO₂)

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

Quartz

Quartz (Silicon Dioxide - SiO2)

Clear Quartz (or Rock Crystal) (Quartz (SiO₂)) — Mineral

Clear Quartz (or Rock Crystal)

Quartz (SiO₂)

Corundum (Corundum (Al2O3)) — Mineral

Corundum

Corundum (Al2O3)

Gneiss (Gneiss (High-grade Regional Metamorphism)) — metamorphic

Gneiss

Gneiss (High-grade Regional Metamorphism)

Gneiss (likely Granitic Gneiss) (Gneiss) — metamorphic

Gneiss (likely Granitic Gneiss)

Gneiss

Gneiss (Pebble) (Gneiss) — metamorphic

Gneiss (Pebble)

Gneiss

Greenstone / Greenschist (Chlorite schist / Meta-basalt) — metamorphic

Greenstone / Greenschist

Chlorite schist / Meta-basalt

Gneiss (with Quartzite and Mica) (Gneiss) — metamorphic

Gneiss (with Quartzite and Mica)

Gneiss

Greenschist (Chlorite Schist) (Greenschist (containing chlorite, actinolite, and epidote)) — metamorphic

Greenschist (Chlorite Schist)

Greenschist (containing chlorite, actinolite, and epidote)

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

Gneiss

High-grade regional metamorphic rock (Foliated)

Gneiss (Gneiss) — metamorphic

Gneiss

Gneiss

Greenstone (Metabasalt / Greenschist facies rock) — metamorphic

Greenstone

Metabasalt / Greenschist facies rock

Gneiss (Gneiss) — metamorphic

Gneiss

Gneiss

Metagabbro / Epidote Gneiss (Epidote bearing Hornblende Gneiss) — metamorphic

Metagabbro / Epidote Gneiss

Epidote bearing Hornblende Gneiss

Nuummite (Antophyllite-Gedrite (Orthorhombic amphiboles)) — metamorphic

Nuummite

Antophyllite-Gedrite (Orthorhombic amphiboles)

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

Banded Gneiss

Gneiss (High-grade Metamorphic Rock)

Banded Gneiss (Gneiss (high-grade metamorphic silicate rock)) — metamorphic

Banded Gneiss

Gneiss (high-grade metamorphic silicate rock)

Greenstone Celt (Polished Stone Axe) (Metamorphosed mafic rock (often Basalt or Diabase)) — metamorphic

Greenstone Celt (Polished Stone Axe)

Metamorphosed mafic rock (often Basalt or Diabase)

Greenstone (Epidisite / Chlorite Schist) (Metabasalt (often contains Epidote Ca2Al2(Fe3+,Al)(SiO4)(Si2O7)O(OH) and Chlorite)) — metamorphic

Greenstone (Epidisite / Chlorite Schist)

Metabasalt (often contains Epidote Ca2Al2(Fe3+,Al)(SiO4)(Si2O7)O(OH) and Chlorite)

Granite Gneiss or Granitoid River Rock (Granitoid / Gneiss) — Metamorphic or Igneous

Granite Gneiss or Granitoid River Rock

Granitoid / Gneiss

Metamorphic or Igneous

Quartz chunk (Silicon dioxide (SiO2)) — mineral

Quartz chunk

Silicon dioxide (SiO2)

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

Yellow Quartz Pebble

Silicon Dioxide (SiO2)

Clear Quartz (Silicon Dioxide (SiO2)) — mineral

Clear Quartz

Silicon Dioxide (SiO2)

Hematite (Hematite (Iron(III) oxide, Fe2O3)) — mineral

Hematite

Hematite (Iron(III) oxide, Fe2O3)

Milky Quartz (Quartz (Silicon Dioxide, SiO2)) — mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Smoky Quartz (Silicon Dioxide (SiO2)) — mineral

Smoky Quartz

Silicon Dioxide (SiO2)

Blue Apatite (Apatite - Ca5(PO4)3(F,Cl,OH) (Calcium phosphate with Fluorine, Chlorine, or Hydroxyl)) — mineral

Blue Apatite

Apatite - Ca5(PO4)3(F,Cl,OH) (Calcium phosphate with Fluorine, Chlorine, or Hydroxyl)

Quartz (Milky or Smoky Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky or Smoky Quartz)

Silicon Dioxide (SiO2)

Red Garnet (Pyrope-Almandine series (Mg3Al2(SiO4)3 to Fe3Al2(SiO4)3)) — mineral

Red Garnet

Pyrope-Almandine series (Mg3Al2(SiO4)3 to Fe3Al2(SiO4)3)

Blue Apatite (Apatite group (Ca5(PO4)3(F,Cl,OH))) — mineral

Blue Apatite

Apatite group (Ca5(PO4)3(F,Cl,OH))

Citrine (Silicon Dioxide (SiO2)) — mineral

Citrine

Silicon Dioxide (SiO2)

Banded Agate (Cryptocrystalline Silicon Dioxide (SiO2)) — mineral

Banded Agate

Cryptocrystalline Silicon Dioxide (SiO2)