Mineral And Metamorphic Rock

Foliated metamorphic rock, likely gneiss or schist

Biotite–quartz–feldspar gneiss/schist; exact identification requires a fresh surface and testing

Gneiss (Metamorphosed Granitic Rock)

Gneiss (composed mainly of quartz, feldspar, biotite, and/or hornblende)

Gneiss

Gneiss

Weathered quartz-rich rock, possibly milky quartz or quartzite

Quartz (SiO₂), likely in a quartzite or silicified matrix

Slate

Slate (foliated metamorphic rock)

Milky Quartz

Silicon Dioxide (SiO2)

Greenstone

Greenschist (Greened Metabasalt)

Polished smoky quartz (likely iron-stained quartz)

Quartz, silicon dioxide (SiO₂); brown coloration may result from irradiation or iron-related staining/inclusions

Quartzite Cobble / Quartz River Pebble

Silicon Dioxide (SiO2) - Quartzite / Quartz

Jasper and Epidote in Quartzite

Metamorphic rock containing microcrystalline quartz, epidote, and jasper

Banded gneiss pebble

Gneiss, typically quartz–feldspar–mica; exact mineral composition requires testing

Granite Gneiss

Gneiss (High-grade Metamorphic Rock)

Green Slate Pebble (Serpentine / Greenschist Pebble)

Greenschist / Low-grade Metamorphic Rock

Quartz-rich metamorphic rock (likely quartzite)

Quartzite; predominantly crystalline quartz (SiO₂), possibly with mica or feldspar impurities

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) with host rock (often Schist or Basalt)

Gneiss

Gneiss (High-grade metamorphic rock)

Granite Gneiss

Gneiss (High-grade Metamorphic Rock)

Gneiss

Gneiss (High-grade Metamorphic Rock)

Foliated metamorphic rock, likely gneiss

Biotite–quartz–feldspar gneiss, possibly migmatitic gneiss

Dark gray rock fragment

Indeterminate from image; possibly weathered basalt or fine-grained metamorphic rock

Pale-green schist fragment

Chlorite–sericite schist, possibly containing epidote or actinolite

Gneiss

Gneiss (High-grade Metamorphic Rock)

Gneiss

Gneiss (High-grade metamorphic rock)

Likely weathered mica schist fragment

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

Schist (Kyanite Schist)

Kyanite-Mica Schist (primarily Al2SiO5, KAl2(AlSi3O10)(OH)2, and SiO2)

Greenshist / Chlorite Schist

Chlorite schist (contains (Mg,Fe)3(Si,Al)4O10(OH)2·(Mg,Fe)3(OH)6)

Weathered metamorphic rock, likely greenschist or amphibolite

Chlorite–actinolite schist/amphibolite; composition likely quartz, feldspar, chlorite, amphibole, and epidote

Quartz

Silicon Dioxide (SiO2)

Gneiss

Metamorphic rock of high-grade regional metamorphism

Rounded gray pebble, likely quartz-rich stone

Indeterminate; possibly quartzite or a weathered granitic pebble

Greenish altered rock, possibly serpentinite or chlorite-rich schist

Tentative: serpentine-group minerals, chiefly antigorite/lizardite, or chlorite–actinolite assemblage

Quartz Crystal Fragment

Silicon Dioxide (SiO2)

Quartz (Clear Quartz)

Silicon Dioxide (SiO2)

Limonite pseudomorph after pyrite

Goethite / Limonite pseudomorph after Pyrite (Fe3+O(OH) replacing FeS2)

Lapis Lazuli (polished cabochon/sphere)

Na8[Al6Si6O24]Sn with accessory minerals (Pyrite, Calcite)

Brecciated marble (decorative stone slab)

Calcite-rich marble breccia; chiefly calcite (CaCO₃), potentially with dolomite and minor iron oxides

Quartz Vein Rock

Silicon Dioxide (SiO2)

Reddish-brown crystalline rock, possibly weathered granite or garnet-bearing schist

Indeterminate; likely quartz–feldspar–mica rock with iron oxides, potentially garnet-bearing

Likely quartz-rich rock fragments

Uncertain; probable quartz with iron-oxide staining, possibly mica-bearing metamorphic rock

Raw quartz fragment

Quartz (SiO₂), likely milky or included quartz

Gneiss (Metamorphic Rock)

Gneiss

Quartz

Silicon Dioxide (SiO2)