Metamorphic Rock

Vein-bearing metamorphic rock, likely gneiss or schist

Quartz-feldspar–mica metamorphic rock; exact identification requires testing

Iron-rich metamorphic rock, likely banded iron formation fragment

Hematite–magnetite-rich quartzite (BIF); Fe₂O₃/Fe₃O₄ with SiO₂

Dark gray foliated metamorphic rock, likely slate or phyllite

Slate/phyllite; chiefly quartz, mica, and chlorite

Dark foliated metamorphic rock, probably schist

Mica schist, likely quartz–muscovite/biotite schist

Quartz-rich metamorphic rock (likely quartzite)

Quartzite, dominantly crystalline SiO₂, with probable iron-oxide staining and minor feldspar/mica

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly crystalline quartz (SiO₂), possibly with mica and feldspar

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly crystalline SiO₂, possibly with iron-oxide staining and minor feldspar or mica

Likely quartz-rich metamorphic rock (quartzite or milky quartz)

Quartzite; predominantly quartz (SiO₂), possibly with feldspar and iron-oxide staining

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly microcrystalline to granular SiO₂, possibly with mica and feldspar

Weathered quartz-rich metamorphic rock, possibly quartzite

Quartzite; predominantly quartz (SiO₂), with minor feldspar, mica, and iron-oxide staining

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly quartz (SiO₂), with minor feldspar, mica, and iron-oxide staining

Likely quartz-rich metamorphic rock (quartzite or quartz-veined schist)

Quartzite/siliceous schist; chiefly quartz (SiO₂), with probable mica and iron-oxide staining

Dark metamorphic rock, possibly schist

Mica schist (probable; commonly quartz + muscovite/biotite, with possible graphite or chlorite)

Tumbled gray-green metamorphic rock, likely serpentinite or chlorite schist

Serpentinite/chlorite-rich ultramafic metamorphic rock; commonly dominated by antigorite, lizardite, or chlorite with minor magnetite and talc

Quartz-rich metamorphic rock, likely milky quartz or quartzite

Quartz (SiO₂); possibly quartzite composed predominantly of recrystallized quartz

Blue-gray metamorphic rock, likely slate or phyllite

Slate/phyllite; chiefly quartz, muscovite/illite, chlorite, and minor feldspar

Mica Schist

Mica Schist

Schist with Quartz Veins

Schist with Quartz (SiO2)

Dark gray metamorphic rock, likely slate or phyllite

Fine-grained foliated rock composed mainly of mica, chlorite, and quartz; exact identification requires testing

Dark weathered igneous rock, likely basalt

Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine or iron oxides

Granite-like granitic rock

Crystalline plutonic rock, primarily quartz, feldspar, and mica/amphibole

Pyrite Schist

Metamorphic rock containing FeS2 (Pyrite) with mica and quartz

Mica schist

Muscovite–biotite schist, commonly with quartz and feldspar

Granite with Epidote

Granite, containing quartz, feldspar, and epidote

Granite or granitic pebble

Granite; chiefly quartz (SiO₂), feldspar, and mica/amphibole

Weathered granite or granitic gneiss

Granite; primarily quartz, feldspar, and mica

Quartz-veined Metamorphic Rock

Quartz Vein in Phyllite or Schist (SiO2 in Silicate Matrix)

Quartz vein in metamorphic rock

Crystalline Silicon Dioxide (SiO2) in Host Rock

Likely slate or fine-grained metamorphic rock

Slate; predominantly microcrystalline quartz, mica, and clay minerals

Dark gray fine-grained stone, likely basalt

Basalt; chiefly plagioclase feldspar and pyroxene, commonly with minor olivine and iron oxides

Gneiss (foliated metamorphic rock)

Gneiss

Banded Gneiss

Gneiss (Metamorphic Rock)

Banded Metamorphic Rock (likely Quartzite or Serpentinite/Soapstone)

Metamorphic Rock (possibly a banded Quartzite or a foliated Serpentinite/Talc Schist based on appearance, general term for such a rock is 'Banded Metamorphic Rock' or 'Gneiss' if pronounced banding of different minerals)

Gneiss

Gneiss (Metamorphic Rock)

Gneiss

Gneiss (Metamorphic Rock)

Gneiss

Gneiss (Metamorphic Rock)

Banded Gneiss Pebble

Gneiss (Metamorphic Rock)

Gneiss

Gneiss (Metamorphic rock)

Gneiss

Gneiss (Metamorphic Rock)

Gneiss

Gneiss (Metamorphic Rock)

Slate

Foliated Metamorphic Rock

Foliated Gneiss

Gneiss (Metamorphic Rock)