Metamorphic Mineral

Quartz with Mica / Chlorite Inclusion

Silicon Dioxide (SiO2) with Phyllosilicate minerals

Biotite-rich gneiss with a dark mafic band

Banded gneiss, likely quartz–feldspar–biotite gneiss (exact minerals uncertain from the image)

Banded amphibolite (hornblende schist)

Amphibolite, chiefly hornblende + plagioclase feldspar, commonly with biotite and quartz

Greenstone

Metabasalt / Chlorite Schist

Mica-rich metamorphic rock, likely schist

Muscovite–biotite schist, possibly with quartz and feldspar

Zebra marble

Banded calcite marble, commonly called zebra marble; chiefly calcite (CaCO₃), sometimes with dolomite and dark silicate or carbonaceous minerals

Likely slate fragment

Slate; predominantly fine-grained mica/clay minerals and quartz

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

Weathered foliated metamorphic rock, likely schist or phyllite

Micaceous quartz–feldspar schist/phyllite; exact identification requires microscopy or testing

Likely weathered mica schist fragment

Mica schist, chiefly muscovite/biotite mica with quartz and feldspar

Foliated metamorphic rock, likely schist

Mica schist or chlorite schist; composition commonly quartz + mica/chlorite ± feldspar

Likely slate fragment

Slate; fine-grained foliated metamorphic rock, commonly quartz–mica–chlorite rich

Weathered metamorphic pebble, likely greenstone

Probable greenschist or chlorite-rich metabasalt; exact identification requires testing

Epidote (Greenstone)

Calcium aluminum iron silicate hydroxide Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH)

Banded gneiss (likely orthogneiss or paragneiss)

Gneiss; composition commonly quartz + feldspar + mica, with possible amphibole/biotite

Epidote

Epidote - Ca2(Al,Fe)3(SiO4)3(OH)

Slate fragment

Slate; predominantly fine-grained mica/clay minerals, commonly muscovite, chlorite, and quartz

Blue-gray metamorphic rock, possibly slate or phyllite

Likely quartz–mica-rich phyllite/slate; exact identification requires testing

Schist with Biotite and Quartz

Biotite-Quartz Schist (Fe,Mg,Al silicate mix)

Banded gneiss or gneissic schist

Quartz–feldspar–mica gneiss; exact mineral proportions require testing

Greenschist / Serpentinite

Metamorphic rock rich in chlorite/actinolite/serpentine

Banded gneiss

Quartzo-feldspathic biotite gneiss, possibly garnet-bearing

Slate

Slate; fine-grained foliated metamorphic rock, chiefly quartz, mica, and clay minerals

Gneiss with Quartz Vein

Metamorphic Gneiss with Quartz (SiO2) and Feldspar Injection

Greenish-gray slate fragment

Slate; fine-grained metamorphosed mudstone, commonly mica- and chlorite-bearing

Banded gneiss

Quartz–feldspar–biotite gneiss (exact minerals uncertain from the photo)

Banded gneiss

Gneiss, commonly quartz–feldspar–mica gneiss

Epidote

Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Weathered quartzite or quartz-rich metamorphic rock

Quartzite, predominantly microcrystalline SiO₂, possibly with mica, feldspar, and iron-oxide staining

Serpentine-bearing metamorphic rock (likely chromite/vesuvianite-bearing serpentinite)

Serpentinite, chiefly serpentine-group minerals [(Mg,Fe)₃Si₂O₅(OH)₄], with dark accessory minerals

Likely garnet-bearing mica schist

Mica schist, possibly containing garnet (garnet–mica schist)

Epidote

Epidote, Ca₂(Al,Fe³⁺)₃(SiO₄)₃(OH); commonly occurring as an epidote-rich rock

Wollastonite

Calcium Inosilicate, CaSiO3

Banded gneissic rock

Gneiss, likely quartz–feldspar–biotite gneiss

Greenschist / Serpentinite Cobble

Greenschist (composed primarily of chlorite, actinolite, and epidote)

Quartz-bearing metamorphic rock, likely quartzite

Quartzite, predominantly SiO₂, with possible feldspar and mica impurities

Banded gneiss pebble

Biotite–quartz–feldspar gneiss (composition variable)

Greenstone / altered mafic rock

Likely chlorite–epidote–actinolite schist or altered basalt (greenstone); exact identification requires thin-section or chemical testing.

Greenstone / epidote–chlorite schist (tentative)

Epidote–chlorite schist, likely containing actinolite and quartz/feldspar

Garnet Amphibolite (or Garnet Gneiss)

Garnet amphibolite / Garnet-bearing metamorphic rock

Pink-red faceted gemstone, possibly synthetic corundum or spinel

Uncertain; possible ruby (corundum, Al₂O₃) or red spinel (MgAl₂O₄)

Fuchsite (Chrome Mica)

K(Al,Cr)2(AlSi3O10)(OH)2