Metamorphic Rock

Gneiss

Gneiss (High-grade regional metamorphic rock)

Mixed rounded river pebbles, likely basalt and granite

Basalt (fine-grained mafic rock) and granite/granitoid (quartz–feldspar rock)

Unakite / Feldspar Veined Metamorphic Pebble

Metamorphic Rock with K-Feldspar, Epidote, and Quartz

Tiger's Iron

Pseudomorphic Quartz Aggregate (contains SiO2 with Fe2O3 and FeOOH)

Granite Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Mica Schist with Pyrite

Mica Schist (FeS2 containing)

Green Aventurine

Silicon Dioxide (Quartz with Fuchsite inclusions), SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Gneiss (High-Grade Metamorphic Rock)

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

Gneiss

Metamorphic rock of high-grade regional metamorphism

Gneiss and Igneous Rock Collection

Foliated Metamorphic Rock (Gneiss) / Igneous Rocks

Gneiss (Metamorphic Pebble)

Metamorphic Rock (Quartz-Feldspar-Biotite Gneiss)

Polished ruby-in-fuchsite (probable)

Corundum (Al₂O₃) with green fuchsite mica (Cr-muscovite), possibly zoisite/amphibole

Blue Quartzite

Quartzite (primarily SiO2 with inclusions like Dumortierite or Magnesio-riebeckite)

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Greenstone

Metabasalt / Greenstone (low-grade metamorphic rock)

Quartzite with Mica / Gneiss Pebble

Metamorphic Rock (Quartz-Feldspar-Mica aggregate)

Rounded granite or granitic pebble

Granite; mainly quartz, feldspar, and mica (exact identification is uncertain from the photograph)

Quartzite with Mica Matrix

Metamorphic Quartz-Mica Schist/Quartzite

Schist

Mica Schist (Medium-grade metamorphic rock)

Gneiss (with Granite/Pegmatite Vein)

Foliated Metamorphic Rock (Quartz-Feldspar Gneiss)

Gneiss with Quartz Veining

Gneiss (High-grade Regional Metamorphic Rock)

Greenstone / serpentinite-like metamorphic rock

Probable serpentinite-rich greenschist; commonly dominated by serpentine-group minerals, chlorite, actinolite, and magnetite

River Pebble (Quartzite / Sandstone)

SiO2 (Quartz-rich sedimentary/metamorphic rock)

Polished river pebble, likely granite or granitic gneiss

Quartz–feldspar–mica aggregate; possibly biotite granite (compositionally near granite)

Gneiss (Green Gneiss)

Gneiss (High-grade Regional Metamorphic Rock)

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Gneiss (High-grade Metamorphic Rock)

Gneiss (Metamorphic silicate rock)

Garnet Amphibolite (or Garnet Gneiss)

Garnet amphibolite / Garnet-bearing metamorphic rock

Weathered, iron-stained rock (likely metamorphic)

Indeterminate from photograph; possibly quartz-rich gneiss or schist

Serpentinite (likely antigorite-rich)

Serpentine-group rock; chiefly antigorite, lizardite, and/or chrysotile, approximately Mg3Si2O5(OH)4

Red Quartzite

Quartzite (primarily SiO2)

Gneiss (specifically Pink Gneiss)

Gneiss (high-grade regional metamorphic rock)

Granite Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Greenschist / Serpentinite

Metamorphic rock rich in chlorite/actinolite/serpentine

Weathered banded gneiss (probable)

Gneiss; quartz–feldspar–mica metamorphic rock

Quartzite

Metamorphic rock primarily composed of Quartz (SiO2)

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Quartzite Pebble

Metamorphic Rock (chiefly Silicon Dioxide, SiO2)

Mica Schist

Metamorphic Rock (rich in Muscovite or Biotite mica)

Quartzite (with inclusions)

SiO2 (Silicon Dioxide) rich Metamorphic Rock