Metamorphic (Low Grade)

Veined marble or calcitic limestone

Calcite-dominant carbonate rock (CaCO₃), likely marble

Slate

Slate; predominantly fine-grained mica- and clay-mineral rock, commonly derived from shale

Dark metamorphic rock, likely slate or phyllite

Fine-grained foliated metamorphic rock; commonly dominated by quartz, mica, and chlorite

Polished banded stone, likely tiger’s-eye

Tiger’s-eye quartz (fibrous chalcedony/quartz, SiO₂), possibly iron-rich quartzite

Greenstone (Chert)

Microcrystalline Silica (SiO2) with chlorite/epidote inclusions

Soapstone (steatite), possibly talc-rich schist

Steatite; predominantly talc, Mg₃Si₄O₁₀(OH)₂, with possible chlorite, mica, and carbonates

Engraved polished dark stone (likely slate or basalt)

Probable fine-grained slate (microcrystalline phyllosilicates), possibly basalt; exact identification requires testing

Greenstone Celt (Polished Stone Axe)

Metamorphosed mafic rock (often Basalt or Diabase)

Anthracite Coal

Anthracite

Epidote with Quartz and Feldspar

Ca2(Al2,Fe3+)(SiO4)3(OH) (Epidote complex)

Fine-grained dark metamorphic rock, likely slate or phyllite

Slate/phyllite, composed mainly of mica-group minerals, quartz, and clay-derived minerals

Weathered metamorphic rock, likely schist or slate

Foliated pelitic metamorphic rock; commonly muscovite–chlorite schist or phyllite

Tumbled milky quartz

Quartz (SiO₂), microcrystalline or massive variety

Epidote with Magnetite/Hematite inclusions

Epidote (Ca2(Al2,Fe3+)(SiO4)3(OH)) with Iron Oxides

Green Schist

Greenschist (composed primarily of Chlorite, Actinolite, and Epidote)

Reddish foliated metamorphic rock, likely phyllite

Phyllite, typically quartz–mica–chlorite with iron-oxide staining

Greenstone / Graywacke

Metagraywacke (Chlorite-grade schistose rock)

Serpentinite (likely)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, commonly with magnetite and minor carbonates

Quartz / Quartzite

Silicon Dioxide (SiO2)

Fuchsite

Chromium-rich Muscovite (KAl2(AlSi3O10)(OH,F)2 with Cr replacements)

Quartz with Epidote

Silicon Dioxide (SiO2) with Calcium Aluminum Iron Silicate [Ca2(Al,Fe)3(SiO4)3(OH)]

Greenstone, likely altered basalt (possibly serpentinite)

Metabasalt/greenschist; commonly chlorite–actinolite–epidote ± serpentine

Tumbled greenstone, likely serpentine or altered basalt

Probable serpentinite (Mg-rich phyllosilicates, chiefly antigorite/lizardite) or chlorite-rich basalt

Greenschist (Chlorite Schist)

Greenschist (Metamorphic rock dominated by chlorite, actinolite, and epidote)

Tumbled ruby-bearing corundum

Corundum (Al₂O₃), likely ruby variety

Rounded, striated pebble—likely slate or fine-grained metamorphic rock

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

Rough Emerald

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Jadeite

Jadeite (NaAlSi2O6)

Tumbled greenstone, likely serpentine or altered basalt

Serpentine-group minerals, chiefly Mg₃Si₂O₅(OH)₄; possibly chlorite/epidote-bearing mafic rock

Pyrite-bearing metamorphic rock (likely greenschist or phyllite)

Quartz–chlorite–mica schist/phyllite with disseminated pyrite (FeS₂)

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals like Antigorite, Lizardite, and Chrysotile)

Quartz fragment

Quartz (silicon dioxide, SiO₂)

Rounded greenstone cobble

Likely altered basalt/greenstone; commonly chlorite–actinolite–epidote rich

Banded gneiss

Gneiss; typically quartz–feldspar–mica assemblage

Likely raw epidote or altered amphibole crystal

Epidote, Ca₂(Al,Fe³⁺)₃(SiO₄)₃(OH); identification is tentative from the image

Jasper pebble

Silicon Dioxide (SiO2) with iron oxide impurities

Jadeite (Jade)

Jadeite (NaAlSi2O6)

Tumbled green aventurine quartz

Aventurine quartz; microcrystalline SiO₂ with dispersed mica or fuchsite inclusions

Greenschist (Greenstone River Pebble)

Greenschist (Chlorite Schist)

Greenstone, likely chlorite-rich schist

Chlorite schist; chiefly chlorite, actinolite/amphibole, feldspar, and quartz

Polished tiger’s-eye

Quartz variety with fibrous crocidolite pseudomorphs; mainly SiO₂

Black slate

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