Metamorphic Rock (Primarily Composed Of Minerals)

Browse metamorphic rock (primarily composed of minerals) specimens identified by the Rock Identifier community.

Ferruginous Sandstone (Ironstone)

Arenite with Limonite/Goethite cement

sedimentary

Greenstone

Greenschist (commonly containing Chlorite, Actinolite, and Epidote)

metamorphic

Blue Quartz (Aventurine)

Silicon Dioxide (SiO2) with inclusions of Dumortierite or Magnesio-riebeckite

mineral

Blue Calcite

Calcium Carbonate (CaCO3)

mineral

Yellow Aventurine

Silicon Dioxide (SiO2) with inclusion of Mica

Mineral (Variety of Quartz)

Limonite-stained Quartz / Quartzite

Silicon Dioxide (SiO2) with iron hydroxides (FeO(OH)·nH2O)

sedimentary or metamorphic

Granite

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

igneous

Gneiss

High-grade regional metamorphic rock (Foliated)

metamorphic

Ventifact

Eolian Ventifact (often composed of basalt, chert, or quartzite)

sedimentary

Yellow Quartzite River Cobble

Meta-quartzite (SiO2 with iron oxide staining)

metamorphic

Jade (Jadeite/Nephrite)

NaAlSi2O6 (Jadeite) / Ca2(Mg,Fe)5Si8O22(OH)2 (Nephrite)

metamorphic

Jadeite Jade

NaAlSi2O6 (Sodium Aluminum Silicate)

metamorphic

Green Tourmaline

Verdelite (Silicate mineral); Na(Li,Al)3Al6(BO3)3Si6O18(OH)4

mineral

Green Aventurine

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

metamorphic

Fulgurite

Fulgurite (Lechatelierite-rich variety)

metamorphic

Amygdaloidal Basalt

Amygdaloidal Basalt (Ca-rich Plagioclase, Pyroxene, and Olivine)

igneous

Biotite Schist

Biotite Mica Schist [K(Mg,Fe)3AlSi3O10(OH,F)2]

metamorphic

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic volcanic rock including secondary mineral infills)

Igneous

Quartz (Variety of Rough Mineral Specimens)

Silicon Dioxide (SiO2)

mineral

Yellow Quartz (Citrine Quartz Pebble)

Silicon Dioxide (SiO2)

mineral

Quartzite with Quartz Vein

Quartzite (primarily SiO2)

metamorphic

Quartz Vein in Gneiss or Basalt

Milky Quartz (SiO2) within Metamorphic Host Rock

Metamorphic or Igneous with Mineral Inclusion

Iron-Stained Quartzite

Recrystallized Meta-Quartzite (primarily SiO2)

metamorphic

Black Sapphire

Corundum (Al2O3 with iron and titanium impurities)

mineral

Banded Onyx (Green Onyx)

Banded Calcite or Travertine (CaCO3)

Sedimentary

Jasper in Basalt Matrix

Silicon Dioxide (SiO2) with impurities; Chalcedony

sedimentary (secondary mineral) within igneous

Orange Calcite

Calcite (Calcium Carbonate, CaCO3)

mineral

Greenstone / Greenstone Pebble

Greenschist (metamorphosed basalt or gabbro)

metamorphic

Moonstone

Orthoclase (Potassium Feldspar) - (K,Na)AlSi3O8

mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Mineral

Pyrite in Matrix (Quartz/Schist)

Iron Sulfide (FeS2)

mineral

Quartzite Pebble

Quartzite (primarily SiO2)

metamorphic

Limonite (often after Hematite or Goethite)

Limonite (FeO(OH)·nH2O)

mineral

Greenschist (Greenstone)

Chlorite schist (primarily Chlorite-Epidote-Actinolite-Albite)

metamorphic

Milky Quartz

Silicon Dioxide (SiO2)

mineral

Anyolite (Ruby in Zoisite)

Zoisite with inclusions of Corundum; Ca2Al3(SiO4)3(OH) + Al2O3

metamorphic

Red Quartzite

Quartzite (primarily SiO2)

metamorphic

US Penny

Cuprum (Copper: Cu) and Zincum (Zinc: Zn) Alloy

Man-made object (metal alloy)

Blue Quartzite

Quartzite with inclusions (often Dumortierite or Magnesio-riebeckite)

metamorphic

Pebble (likely a type of sandstone or quartzite pebble)

Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.

Sedimentary rock

Smoky Quartz (Tumbled)

Silicon Dioxide (SiO2)

mineral

Tiger's Eye

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

metamorphic