Metamorphic (Low Grade)

Jadeite Jade

NaAlSi2O6 (Sodium Aluminum Silicate)

Greenstone (likely chlorite-rich metamorphic rock)

Chlorite-rich greenschist; exact identification requires testing

Likely polished slate

Slate, a fine-grained metamorphic rock composed mainly of quartz, mica, and chlorite

Tumbled greenstone (likely serpentine-rich)

Serpentinite or chlorite/epidote-rich greenstone; exact identification requires testing

Quartz vein in greenstone/altered mafic rock

Quartz (SiO₂) with chlorite–epidote-rich metabasalt or greenstone

Polished tiger’s-eye

Tiger’s-eye quartz (fibrous chalcedony/quartz, SiO₂)

Argillite (with Barnacles)

Argillite (metamorphosed mudstone/shale)

Weathered gray metamorphic rock, likely phyllite or slate

Micaceous quartz–phyllosilicate rock; commonly quartz + muscovite/illite ± chlorite

Dark gray slate or phyllite cobble

Slate–phyllite, composed mainly of fine-grained mica, quartz, and chlorite

Tumbled greenstone (likely serpentine or chlorite-rich metamorphic rock)

Serpentinite, approximately Mg₃Si₂O₅(OH)₄, or chlorite-rich greenstone

Unakite (likely epidote–feldspar rock)

Epidote–K-feldspar–quartz aggregate; commonly approximated as pink orthoclase/microcline + green epidote + quartz

Tumbled dark stones, likely basalt and slate

Basalt (fine-grained mafic rock) and slate (foliated metamorphic rock); exact identification is uncertain from the image

Fine-grained gray stone, likely slate or weathered basalt

Indeterminate; possible slate (foliated phyllite-grade shale)

Dark metamorphic rock, likely slate or phyllite

Foliated metapelite; commonly mica-rich quartz–clay mineral assemblage

Slate

Slate; fine-grained metamorphosed shale, commonly mica- and chlorite-rich

Slate

Slate; primarily fine-grained mica, chlorite, quartz, and clay minerals

Greenstone with Magnetite Veins

Metabasalt (Greenstone)

Polished dark greenstone with quartz vein

Likely chlorite-rich metabasalt or greenschist with a quartz–feldspar vein

Banded gneiss pebble

Gneiss, typically quartz–feldspar–mica assemblage

Almandine Garnet

Almandine, Fe3Al2(SiO4)3

Dark slate pebble

Slate, predominantly fine-grained mica and clay-derived minerals

Quartz-rich pegmatitic rock, probably granitic gneiss

Quartz–feldspar–mica gneiss; locally pegmatitic granite

Dark gray metamorphic rock fragment

Likely slate or fine-grained schist; mineral composition cannot be confirmed from the image

Epidote in Granite Gneiss

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

Schist

Schist (various mineral compositions)

Gneiss

Foliated quartz–feldspar–mica gneiss

Iron-rich breccia or hematite-bearing jasper

Hematite–quartz jasper (silica-rich ironstone), possibly brecciated

Weathered quartz-rich rock, possibly milky quartz or quartzite

Quartz (SiO₂), possibly quartzite with iron-oxide and dark-mineral inclusions

Weathered quartz-rich rock, possibly quartzite

Quartzite; predominantly microcrystalline quartz (SiO₂)

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

Quartz (SiO₂), possibly quartzite with limonite/goethite iron oxides

River Quartzite Pebble

Quartzite (primarily SiO2)

Greenstone / Greenstone Pebble

Greenschist (metamorphosed basalt or gabbro)

Jadeite Jade

NaAlSi2O6 (Sodium Aluminum Silicate)

Quartz with Chlorite or Hornblende inclusions

Silicon dioxide (SiO2) with phyllosilicate or amphibole inclusions

Weathered greenish-gray rock fragment, likely chlorite-rich schist

Tentatively chlorite schist; exact identification requires closer examination

Dark metamorphic cobble, likely slate or phyllite

Foliated metamorphic rock, probably carbonaceous slate/phyllite; exact identification requires testing

Likely tiger’s-eye rough

Quartz-rich fibrous rock, chiefly SiO₂ with iron-oxide-stained crocidolite (riebeckite) fibers

Greenstone (likely altered basalt)

Metabasalt, commonly composed of actinolite, chlorite, epidote, albite, and quartz

Slate or fine-grained shale

Slate; predominantly quartz, mica, and clay-derived minerals

Greenstone / Basalt

Metabasalt (often containing Chlorite, Epidote, and Actinolite)

Blue Kyanite

Kyanite (Al2SiO5)

Brecciated Jasper (Polished)

Silicon Dioxide (SiO2) with Iron Oxide Impurities