Mineral In Metamorphic Rock

Dark garnet-bearing metamorphic rock (probable garnet schist/amphibolite)

Garnet schist or garnet amphibolite; chiefly quartz, mica/amphibole, feldspar, and almandine–pyrope garnet

Dark gray metamorphic rock, likely slate or phyllite

Fine-grained foliated pelite; commonly mica- and chlorite-rich, with quartz and feldspar

Schist

Mica Schist (Medium-grade Metamorphic Rock)

Polished dark stone, possibly black tourmaline or a dark pebble

Undetermined; image lacks detail for reliable identification

Gneiss

Gneiss (Foliated Metamorphic Rock)

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

Dark metamorphic rock, likely schist or slate fragment

Indeterminate; possibly biotite schist, chlorite schist, or slate

Dark metamorphic rock, likely schist or amphibolite

Biotite–quartz schist / amphibolite (tentative; image alone is insufficient for exact identification)

Banded amphibolite (hornblende schist)

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

Banded Slate or Siltstone with Quartz/Calcite Veins

Protolith-derived Siltstone or Slate (varies based on degree of metamorphism)

Quartz Vein in Host Rock

Hydrothermal Quartz (SiO2) in Slates/Schists

Greenschist

Greenschist (chlorite-epidote schist)

Likely quartz-bearing rock or mineral fragment

Indeterminate; possibly quartz (SiO₂) with iron-oxide staining and darker matrix

Schist

Schist (Crystalline metamorphic rock)

Milky Quartz (Carved Star Beads)

Silicon Dioxide (SiO2)

Quartzite with Garnet inclusion

Metamorphic Quartz-rich Rock

Banded gneiss

Foliated gneiss, likely quartz–feldspar–mica gneiss

Gneiss

Foliated Metamorphic Rock (Gneiss)

Green Schist (Greenschist)

Greenschist facies metamorphic rock

Gneiss

Gneiss (foliated metamorphic rock)

Weathered granite or granitic gneiss

Granite; chiefly quartz, feldspar, and mica, possibly with gneissic foliation

Chlorite-rich metamorphic rock, likely greenschist

Greenschist; commonly composed of chlorite, actinolite, epidote, albite, and quartz

Weathered quartz-rich metamorphic rock, likely quartzite

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

Dark mafic metamorphic rock, likely amphibolite

Amphibolite; chiefly hornblende amphibole and plagioclase feldspar

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly crystalline SiO₂, with possible iron-oxide and dark mica/mineral inclusions

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Quartz Vein in Basalt or Slate

Hydrothermal quartz vein traversing mafic host rock

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Raw Calcite

Calcium Carbonate (CaCO3)

Shale (possibly Carbonaceous or Oil Shale)

Argillaceous Sedimentary Rock

Fuchsite Gneiss or Schist

Muscovite (variety Fuchsite) within Metamorphic Host Rock

Banded Agate (Gray/Brown)

Silicon Dioxide (SiO2)

Orthoclase Feldspar

Potassium aluminum silicate (KAlSi3O8)

Dark gray metamorphic rock, likely slate or phyllite

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

Quartz Vein in Greenstone

Hydrothermal Quartz (SiO2) with Chlorite/Epidote Schist host rock

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Polished metallic sulfide-bearing pebble

Likely pyrite-bearing slate, schist, or sulfide-rich ore; exact identification requires testing

Gneiss

Gneiss (Foliated Metamorphic Rock)

Quartz

SiO2 (Silicon Dioxide)

Blue Calcite

Calcium Carbonate (CaCO3)

Gneiss

High-grade metamorphic rock (Gneiss)

Banded gneiss (probable)

Gneiss, commonly quartz–feldspar–mica bearing