Metamorphic Mineral

Gneiss

Metamorphic rock of high-grade regional metamorphism

Banded gneiss pebble

Quartz–feldspar gneiss, possibly with biotite or amphibole

Quartz with Muscovite Mica

Silicon Dioxide (SiO2) with Potassium Aluminum Silicate Hydroxide Fluoride (KAl2(AlSi3O10)(F,OH)2)

Quartz with Actinolite or Tourmaline inclusions

Silicon Dioxide (SiO2) with Ca2(Mg,Fe)5Si8O22(OH)2 or Tourmaline group inclusions

Serpentinite (probable)

Serpentinite, a rock composed chiefly of serpentine-group minerals such as antigorite, lizardite, or chrysotile

Green serpentine-rich rock (possibly serpentinite)

Serpentinite, composed chiefly of serpentine-group minerals (e.g., lizardite, antigorite, or chrysotile)

Weathered granitic gneiss

Quartz–feldspar–biotite gneiss (likely granitic gneiss)

Orthoclase Feldspar with Quartz

Orthoclase (KAlSi3O8)

Iron-stained quartz vein rock

Quartz-rich vein material, predominantly SiO₂, with iron oxyhydroxides (goethite/limonite) and likely sulfide alteration

Chrysotile Asbestos

Mg3Si2O5(OH)4

Blue apatite (likely dyed or enhanced)

Apatite group; fluorapatite, Ca5(PO4)3F, is the common blue variety

Granitic Gneiss

Gneiss (high-grade metamorphic rock)

Yellow serpentine (likely serpentine-rich rock)

Serpentinite; chiefly serpentine-group minerals, such as antigorite, lizardite, and chrysotile

Weathered gneiss

Foliated gneiss, chiefly quartz–feldspar–mica

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Possibly garnet-bearing rock fragment

Unidentified reddish-brown mineral or rock; the image is insufficient for a reliable species identification.

Granitic gneiss (weathered, rounded cobble)

Foliated granitoid; primarily quartz, feldspar, and mica (composition commonly approximates granite)

Gneiss

Foliated Metamorphic Rock (Gneiss)

Schist

Crystalline Metamorphic Rock (Schistose)

Likely mica schist

Mica-rich schist, probably biotite–quartz–feldspar schist

Likely amphibolite

Amphibolite, composed mainly of hornblende (amphibole) and plagioclase feldspar

Garnet-bearing rock (likely almandine garnet in a metamorphic matrix)

Almandine garnet, Fe₃Al₂(SiO₄)₃; host rock is uncertain from the image

Polished rhodonite

Rhodonite, manganese inosilicate (MnSiO₃)

Banded gneiss

Foliated gneiss, likely quartz–feldspar–mica-rich; exact mineral composition cannot be confirmed from the image

Green Aventurine

Quartz (SiO2) with fuchsite inclusions

Pyrite Nodules / Weathered Pyrite

Iron Sulfide (FeS2)

Rounded gray-green rock, likely gneiss

Gneiss (tentative; mineral composition and texture cannot be confirmed from the image)

Likely muscovite mica

Muscovite, KAl₂(AlSi₃O₁₀)(OH)₂

Quartz Vein in Hematitic Siltstone

Hydrothermal Quartz (SiO2) in Ferriferous Matrix

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Coarse-grained gray metamorphic rock, likely gneiss

Biotite–quartz–feldspar gneiss (probable)

Morganite and Aquamarine (Beryl) Bracelet

Beryllium aluminum silicate, Be3Al2(SiO3)6

Slate

Slate; fine-grained metamorphosed shale, commonly composed of quartz, illite/muscovite, and chlorite

Likely blue-green kyanite crystal

Kyanite, Al₂SiO₅

Likely garnet gemstone

Garnet-group silicate; species cannot be determined from the photo (common red varieties include almandine, Fe₃Al₂(SiO₄)₃, and pyrope, Mg₃Al₂(SiO₄)₃).

Green Aventurine

Quartz (SiO2) with fuchsite inclusions

Marble

Metamorphic rock composed of Recrystallized Carbonate Minerals (chiefly CaCO3)

Epidote

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

Tumbled green aventurine (likely)

Quartz, SiO₂, with green fuchsite or other mineral inclusions

Green aventurine (likely)

Quartz, SiO₂, with green fuchsite or other inclusions

Black Tourmaline (Schorl)

Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)

Orange Calcite

Calcium Carbonate (CaCO3)