Igneous And Sedimentary

Uncertain gray metamorphic rock, likely gneiss or schist

Quartz–feldspar–mica rock; exact identification requires close examination

Likely banded gneiss or mica-rich metamorphic pebble

Gneiss; composition likely quartz, feldspar, and biotite/muscovite mica

Banded gneiss (likely migmatitic gneiss)

Gneiss; quartz–feldspar–mica metamorphic rock, locally approaching migmatite

Banded gneiss

Gneiss, commonly quartz–feldspar–biotite gneiss

Banded gneiss pebble

Gneiss, typically quartz–feldspar–mica banded rock

Banded Gneiss

Gneiss (Metamorphic rock of variable mineralogy, often quartz-feldspar base)

Carnelian

Carnelian (a variety of Chalcedony); SiO2 (Silicon Dioxide)

Gneiss (with Quartz and Mica)

Gneiss

Gneiss

Metamorphic rock of high-grade regional metamorphism

Granite / Gneiss (Felsic Metamorphic or Igneous Rock)

Gneiss (or weathered Granite)

Weathered banded metamorphic rock, likely gneiss

Banded gneiss; commonly quartz–feldspar–mica assemblage

Banded gneiss

Foliated, banded gneiss; typically composed of quartz and feldspar with mica or other dark minerals

Banded gneiss pebble

Gneiss, chiefly quartz–feldspar–mica; exact variety indeterminate from image

Banded metamorphic rock, likely gneiss or foliated amphibolite

Quartz–feldspar–mica gneiss or amphibolite; exact identification requires testing

Banded metamorphic rock, likely gneiss

Biotite–quartz–feldspar gneiss (probable); exact identification requires testing

Rounded metamorphic cobble, likely gneiss or amphibolite

Banding-free biotite–quartz–feldspar gneiss or amphibolite; exact identification requires testing

Foliated metamorphic rock, likely gneiss

Biotite–quartz–feldspar gneiss, possibly migmatitic gneiss

Gneiss

Gneiss

Gneiss

Metamorphic Gneiss (High-grade regional metamorphism)

Banded Gneiss with Quartz Vein

Gneiss containing SiO2 (Quartz) intrusion

Quartz (Crystalline Cluster)

Silicon Dioxide (SiO2)

Gneiss

Gneiss

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Banded Gneiss

Gneiss (Metamorphic rock)

Gneiss

Foliated Metamorphic Gneiss

Gneiss (Metamorphosed Pebble)

Gneiss with Quartz/Feldspar banding

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Gneiss

Gneiss

Gneiss

Gneiss (Metamorphic high-grade)

Gneiss (River Cobble)

Gneiss (Foliated Metamorphic Rock)

Banded gneiss pebble

Gneiss, likely quartz–feldspar–mica gneiss

Coarse-grained metamorphic rock, likely gneiss or schist

Probable biotite-quartz-feldspar gneiss/schist; exact identification requires a fresh surface and tests

Polished banded stone, likely gneiss or metasedimentary rock

Banded gneiss (quartz–feldspar–mica assemblage; exact identification requires testing)

Banded metamorphic rock, likely gneiss

Foliated gneiss; chiefly quartz, feldspar, and dark mica/amphibole

Gneiss

High-grade Metamorphic Gneiss

Gneiss

Metamorphic Gneiss

Carnelian

Silicon Dioxide (SiO2) - variety of Chalcedony

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Gneiss (Banded Gneiss)

Gneiss

Polished banded gneiss pebble

Gneiss, commonly quartz–feldspar–biotite gneiss

Bloodstone Jasper (Heliotrope)

SiO2 (Silicon Dioxide) - Cryptocrystalline Quartz

Banded gneiss

Gneiss, likely biotite–quartz–feldspar gneiss