Mineral In Metamorphic Rock

Metamorphic schist, possibly chlorite–biotite schist

Schist; composition likely quartz, feldspar, mica (biotite/muscovite), and chlorite

Likely dark mineral or rock fragment

Indeterminate from image; possibly a dark silicate mineral such as hornblende, biotite, or basalt

Quartz with Muscovite Mica

SiO2 with KAl2(AlSi3O10)(OH)2

Milky quartz (quartzite possible)

Quartz, silicon dioxide (SiO₂)

Tumbled quartz-rich pebble

Quartz (SiO₂), likely with iron-oxide staining and minor inclusions

Tumbled or weathered gneiss

Feldspar–quartz–mica gneiss (composition variable)

Garnet-bearing Schist

Almandine Garnet [Fe3Al2(SiO4)3] in Micaceous Schist

Quartz vein in Schist

Crystalline Silicon Dioxide (SiO2) in Metamorphic Host

Weathered brown mineralized rock

Likely iron-stained quartzite or quartz-rich metamorphic rock; exact identification requires testing

Rounded gray metamorphic rock, likely quartzite or gneiss

Quartz-rich metamorphic rock; exact identification is uncertain from the photograph

Weathered foliated metamorphic rock, likely schist or gneiss

Micaceous schist/gneiss; composition likely quartz, feldspar, mica, and altered mafic minerals

Gneiss

Gneiss (High-grade metamorphic rock)

Green Slate or Metamorphic Rock

Metamorphic rock (chlorite/actinolite-bearing)

Lapis Lazuli

Na8[Al6Si6O24]Sn (Lazurite-rich metamorphic rock)

Tumbled serpentine or serpentinite

Serpentine-group minerals, chiefly antigorite, lizardite, or chrysotile; approximate formula Mg₃Si₂O₅(OH)₄

Banded gneiss

Foliated silicate rock, typically quartz–feldspar–mica gneiss

Biotite mica

Biotite, a potassium–iron–magnesium phyllosilicate mica; approximate formula K(Mg,Fe)₃AlSi₃O₁₀(F,OH)₂

Fuchsite

Chromium-bearing Muscovite - K(Al,Cr)2(AlSi3O10)(OH)2

Garnet Schist or Garnet-bearing Quartzite

Metamorphic rock containing Almandine Garnet (Fe3Al2(SiO4)3) and Quartz (SiO2)

Quartz

Silicon Dioxide (SiO2)

Epidosite with Quartz (Unakite-variant or Jasper)

Epidotized Metasomatite

Polished banded gneiss

Biotite–quartz–feldspar gneiss, locally migmatitic

Banded Serpentine

Serpentine group (subgroup Lizardite or Antigorite) - Mg3Si2O5(OH)4

Epidotite (Unakite-related Epidote)

Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))

Gneiss

Gneiss (High-grade metamorphic rock)

Quartz Pebble

Silicon Dioxide (SiO2)

Likely gneiss

Gneiss, composed chiefly of quartz, feldspar, and mica/amphibole

River Rock (Gneiss/Schist mix)

Foliated Metamorphic Rock (Gneiss)

Iron-stained quartz-rich rock, possibly quartzite or silicified breccia

Quartz (SiO₂)-dominant rock with iron-oxide minerals, chiefly hematite/goethite

Quartz with Iron Oxide Inclusions

Silicon Dioxide (SiO2)

Greenish Feldspathic Rock / Epidote Granite (Unakite-type or Epidote-bearing rock)

Epidotized Metamorphic/Igneous Rock

Slate

Slate (Foliated Metamorphic Rock)

Likely amphibolite (hornblende gneiss or mafic metamorphic rock)

Amphibolite, chiefly hornblende amphibole and plagioclase feldspar, with possible quartz, biotite, or epidote

Quartz

Silicon Dioxide (SiO2)

Banded Agate

Cryptocrystalline variety of Quartz (SiO2)

Gneiss (Metamorphic Pebble)

Gneiss (SiO2-rich metamorphic rock)

Serpentine

Antigorite, Lizardite, or Chrysotile (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4

Milky Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon dioxide (SiO2)

Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Weathered metallic sulfide-bearing rock, possibly schist or gneiss

Indeterminate; likely mica-rich metamorphic rock with iron sulfides or magnetite

Weathered iron-rich metamorphic rock (probable amphibolite or schist fragment)

Likely hornblende–plagioclase amphibolite with biotite/chlorite alteration; exact identification requires testing