Mineral And Metamorphic Rock

Milky quartz with iron staining

Quartz, silicon dioxide (SiO₂)

Likely weathered gneiss

Foliated metamorphic rock, commonly quartz–feldspar–mica gneiss

Almandine Garnet

Almandine (Fe3Al2(SiO4)3)

Milky quartz (rough quartz-rich rock)

Quartz, silicon dioxide (SiO₂); likely massive milky quartz, possibly quartzite

Weathered quartz-rich metamorphic rock, likely gneiss or quartzite

Quartz–feldspar–mica metamorphic rock; exact identification is uncertain from the photograph

Serpentine-rich metamorphic rock

Serpentinite, likely antigorite/lizardite with accessory magnetite or chromite

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartzite

Metamorphic Quartz Rock (SiO2)

Dark mafic metamorphic rock, likely amphibolite

Amphibolite; chiefly hornblende amphibole + plagioclase feldspar

Marble

Metamorphic rock composed of Recrystallized Carbonate Minerals (chiefly CaCO3)

Greenstone (likely metamorphosed basalt)

Metabasalt/greenstone; commonly composed of chlorite, actinolite, epidote, albite, and quartz

Gneiss (Pebble)

Gneiss

Yellow-orange quartz/chalcedony pebble (possibly citrine-bearing)

Quartz, SiO₂; likely microcrystalline chalcedony with iron staining

Yellow Calcite

Calcium Carbonate (CaCO3)

Veined Pebble (Quartz/Calcite Veined Metamorphic/Sedimentary Rock)

Quartz / Calcite Veined Fault Breccia or Metamorphic Pebble

Quartz with Chlorite inclusions

SiO2 with (Mg,Fe)3(Si,Al)4O10(OH)2⋅(Mg,Fe)3(OH)6

Vein-bearing metamorphic rock, likely gneiss or schist

Banded silicate rock; likely quartz–feldspar–mica gneiss with a quartz vein

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Gneiss

Metamorphic Gneiss

Felsic Drill Core (likely Gneiss or Granite)

Felsic Metamorphic Rock (Gneissic profile)

Schist

Mica Schist (Medium-grade Metamorphic Rock)

Gneiss

Gneiss (Foliated Metamorphic Rock)

Blue Tiger's Eye

Crocidolite in Quartz (altered)

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)

Quartzite with Garnet inclusion

Metamorphic Quartz-rich Rock

Banded gneiss

Foliated gneiss, likely quartz–feldspar–mica gneiss

Gneiss

Foliated Metamorphic Rock (Gneiss)

Iridescent schist or phyllite

Micaceous quartz-rich schist/phyllite, likely containing muscovite or chlorite

Coarse-grained metamorphic rock, likely gneiss

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

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

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Quartz Vein in Basalt or Slate

Hydrothermal quartz vein traversing mafic host rock

Milky quartz pebble

Quartz, silicon dioxide (SiO₂)

Milky quartz pebble

Quartz (silicon dioxide, SiO₂)