Metamorphic Or Igneous Alteration

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

Gneiss (River Cobble)

Gneiss (Foliated Metamorphic Rock)

metamorphic

Gneiss

Gneiss (Metamorphic high-grade)

metamorphic

White Quartz Pebble

Silicon Dioxide (SiO2)

mineral

Riverstone (Quartzite/Granite Cobble)

Silicon Dioxide (SiO2) based Quartzite or Silicate-rich Granite

metamorphic or igneous

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

Quartz Pebble

Silicon Dioxide (SiO2)

mineral

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

mineral

Quartz

Silicon Dioxide (SiO2)

mineral

Granitic Pegmatite

Granitic Pegmatite (principally Quartz, Potassium Feldspar, and Mica)

igneous

Granitoid Gneiss with Feldspar Vein

Gneiss (High-grade Metamorphic Rock) with Potassium Feldspar (KAlSi3O8)

metamorphic

Lapis Lazuli

Lapis Lazuli (Complex aggregate of Lazurite, Calcite, and Pyrite)

metamorphic

Greenstone

Greenschist / Greenstone (Chlorite-Epidote facies)

metamorphic

Gneiss (Metamorphic Rock)

Gneiss (high-grade regional metamorphic rock)

metamorphic

Lapis Lazuli

Lapis Lazuli (Mineral composition: Lazurite (Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2, Calcite, and Pyrite)

metamorphic

Gneiss (Metamorphic Cobble)

Gneiss (High-grade Regional Metamorphic Rock)

metamorphic

Greenschist

Greenschist facies rock (containing chlorite, actinolite, albite, and epidote)

metamorphic

Banded Gneiss

Gneiss (quartz-feldspar-biotite metamorphic rock)

metamorphic

Gneiss

Gneiss (high-grade metamorphic rock typically composed of quartz, feldspar, and mica)

metamorphic

Ruby, Emerald, and Sapphire (Corundum and Beryl)

Corundum (Al2O3) and Beryl (Be3Al2Si6O18)

mineral

Gneiss

Gneiss (High-grade metamorphic rock)

metamorphic

Copper Ore (likely Chalcopyrite in Matrix)

Chalcopyrite (CuFeS2)

mineral

Quartz Pebble

Silicon Dioxide (SiO2)

mineral

Feldspar

Potassium Feldspar (KAlSi3O8)

mineral

Smoky Quartz

Quartz (Silicon Dioxide, SiO2)

mineral

Quartz (Milky or Druzy Quartz)

Silicon Dioxide (SiO2)

mineral

Amber and Citrine Quartz

Succinite (Amber) and Silicon Dioxide (SiO2 / Citrine)

mineral

Quartz (Milky or White Quartz)

Silicon Dioxide (SiO2)

mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

mineral

Hematite (Iron Ore)

Hematite (Fe2O3)

mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

mineral

Quartz (Milky/Clear variety)

Silicon Dioxide (SiO2)

mineral

Pink Tumbled Quartz (Dyed)

Silicon Dioxide (SiO2)

mineral

Quartz / Clear Quartz

Silicon Dioxide (SiO2)

mineral

Rough Star Sapphire (Corundum)

Al2O3 (Aluminum Oxide)

mineral

Clear Quartz

Silicon Dioxide (SiO2)

mineral

Quartz (River Pebble)

Silicon Dioxide (SiO2)

mineral

Sunstone

Oligoclase or Andesine (Labradorite) Feldspar (Na,Ca)(Si,Al)4O8

mineral

General Gravel (River Rock/River Stones)

Mixed Lithic Sediments (Conglomerate Clasts)

sedimentary

Moonstone

Adularia (Potassium Aluminum Silicate, KAlSi3O8)

mineral

Quartz (Clear/White)

Silicon Dioxide (SiO2)

mineral

Pink Sapphire

Corundum (Al2O3 with Chromium/Titanium/Iron traces)

mineral

Amazonite

Potassium Feldspar (KAlSi3O8)

mineral