Metamorphic (Altered Igneous Rock)

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

White Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

mineral

Quartz (Iron-Stained Quartz Pebble)

Silicon Dioxide (SiO2)

mineral

Gneiss (specifically Biotite Gneiss)

Gneiss (high-grade metamorphic rock primarily composed of Silicates)

metamorphic

Gneiss

metamorphic

Pebble (likely Sandstone or Granitic Pebble)

Clastic Sediment (or specific rock type, e.g., Arenite, Granitoid Pebble)

Rock (likely Sedimentary)

Gneiss

Gneiss (quartz-feldspar-biotite gneiss)

metamorphic

Banded Gneiss (River Cobble)

Gneiss (a high-grade metamorphic rock)

metamorphic

Pink Anthracite Coal (dyed)

Anthracite Coal (Artificially Colored)

Sedimentary Rock (Altered)

Yellow Quartz (Citrine or Iron-stained Quartz)

Silicon Dioxide (SiO2)

mineral

Pyrite (on Quartz/Host Rock)

Iron Sulfide (FeS₂)

mineral

Greenschist

Chlorite schist (Metamorphic rock dominated by chlorite, epidote, and actinolite)

metamorphic

Gneiss

Gneiss (High-grade regional metamorphic rock)

metamorphic

Feldspathic Gneiss

Feldspathic Gneiss (High-grade regional metamorphic rock)

metamorphic

Magnetite

Magnetite (Fe3O4)

mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Gneiss (Stream-worn Cobble)

Gneiss (Metamorphic rock composed primarily of Quartz, Feldspar, and Mica)

metamorphic

Granitic Gneiss

Gneiss (Polymetamorphic Granitic Gneiss)

metamorphic

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

mineral

Greenstone (Epidote/Chlorite-rich Metabasalt)

Greenschist / Epidosite (Ca2(Al,Fe)3(SiO4)3(OH))

metamorphic

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Quartz (specifically Milky/Gray Quartz)

Silicon Dioxide (SiO2)

mineral

Turquoise

Hydrous phosphate of copper and aluminium - CuAl6(PO4)4(OH)8·4H2O

mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Yellow Quartz (Citrine Quartz Pebble)

Silicon Dioxide (SiO2)

mineral

Serpentine with Quartz Vein

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4 with SiO2 veins

metamorphic

Gneiss (specifically a granitic gneiss cobble)

Gneiss (high-grade regional metamorphic rock)

metamorphic

Gneiss

Gneiss (High-grade regional metamorphic rock)

metamorphic

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

mineral

Quartz (specifically Citrine or Yellow Quartzite pebble)

Silicon Dioxide (SiO2)

mineral

Malachite

Copper carbonate hydroxide [Cu2CO3(OH)2]

Mineral

Quartzite

Quartzite (primarily SiO₂)

metamorphic

Garnet (Red Garnet)

Garnet Group. The red varieties seen in jewelry are typically Almandine (Fe3Al2(SiO4)3), Pyrope (Mg3Al2(SiO4)3), or a mix of the two (pyrope-almandine series).

Mineral (specifically, a variety of the mineral species Pyrope-Almandine Garnet)

Greenschist (Chlorite Schist)

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

metamorphic

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

mineral

Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

metamorphic

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

mineral

Ruby in Zoisite

Ruby (Corundum, Al2O3) in Zoisite (Calcium aluminum silicate hydroxide, Ca2Al3(SiO4)3(OH)) with some Hornblende

Metamorphic Rock (specifically a rock composed of minerals)

Quartz (Milky or Cloudy Quartz)

Silicon Dioxide (SiO2)

mineral

Smoky Quartz in Matrix

Silicon dioxide (SiO2) within Pegmatite/Gneiss

igneous