Metamorphic Rock

Slate

Slate (Foliated metamorphic rock)

Gneiss (River Cobble)

Gneiss (Foliated Metamorphic Rock)

Gneissic Schist

Gneiss-schist (Metamorphic rock)

Schist

Crystalline Metamorphic Rock (Schistose)

Blue-gray metamorphic rock, likely slate or phyllite

Fine-grained foliated metapelite; commonly mica- and chlorite-rich

Gneiss

Banded Metamorphic Rock (Gneiss)

Green Schist (Greenschist)

Greenschist facies metamorphic rock

Quartz Vein in Gneiss or Schist

Metamorphic rock with SiO2 vein

Quartzite Pebble

Metamorphic Rock (rich in SiO2)

Quartzite Cobble

Metamorphic Rock (SiO2 dominated)

Quartzite with Hematite staining

Metamorphic Rock (rich in SiO2)

Greenstone / Greenschist

Greenschist facies metamorphic rock

Quartzite Pebble (with Iron Inclusions)

Metamorphic Rock (Mainly SiO2)

Quartzite

Metamorphic Rock (Mainly SiO2)

Gneiss

Metamorphic Rock (Gneissic texture)

Quartzite pebble

Metamorphic rock (mainly SiO2)

Pink Quartzite

Silica (SiO2) - Metamorphic rock

Greenschist

Greenschist facies metamorphic rock

Schist

Metamorphic Rock (Mica Schist)

Quartzite

Metamorphic rock (primarily SiO2)

Quartzite

Metamorphic Rock (Mainly SiO2)

Raw dark metamorphic rock, likely schist or slate

Mica schist or phyllite; commonly quartz–mica–chlorite aggregate

Granite-like pegmatitic rock

Coarse-grained granitoid, likely quartz–feldspar–mica aggregate

Polished dark gray stone, likely basalt or fine-grained andesite

Basalt/andesite; primarily plagioclase feldspar, pyroxene, and possibly olivine or magnetite

Conical fossil shell or shell fragment

Likely a gastropod shell fragment; exact taxon indeterminate from the image

Blue-gray metamorphic rock, likely slate or schist

Foliated phyllite–schist; chiefly quartz, mica, and chlorite (exact identification requires testing)

Mica-rich metamorphic rock, likely mica schist

Muscovite–biotite schist, possibly with garnet and quartz

Dark gray metamorphic rock, likely slate or phyllite

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

Dark gray metamorphic rock, likely slate or phyllite

Slate/phyllite; chiefly fine-grained mica, chlorite, quartz, and clay-derived minerals

Blue-gray metamorphic rock, likely slate or phyllite

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

Slate

Foliated Metamorphic Rock (Mainly composed of Quartz, Illite, Chlorite)

Likely weathered granite or granitic pegmatite fragment

Granite; primarily quartz (SiO₂), feldspar, and mica

Tanzanite

Zoisite (Ca2Al3(SiO4)(Si2O7)O(OH))

Mica-rich metamorphic rock (likely mica schist)

Mica schist, composed mainly of muscovite and/or biotite with quartz and possibly feldspar

Dark gray metamorphic rock, likely slate or phyllite

Slate/phyllite; commonly quartz–mica–chlorite aggregate

Likely raw mica-bearing metamorphic rock or mineral fragment

Tentatively biotite schist; visually similar dark mica-rich material

Dark gray metamorphic rock, likely slate or phyllite

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

Weathered schist or phyllite

Mica-rich pelitic metamorphic rock; commonly quartz–muscovite/biotite schist or phyllite

Silicified oyster fossil

Fossil oyster shell, commonly Ostrea or Crassostrea, replaced or encrusted by chalcedony/quartz

Likely weathered blue-gray basalt

Basalt, a fine-grained mafic volcanic rock; commonly plagioclase + pyroxene ± olivine and iron oxides

Weathered basaltic rock

Basalt, likely amygdaloidal or altered basalt

Tiger's Eye (Rough)

Pseudomorph of Quartz after Crocidolite (SiO2)