Metamorphic (Low Grade)

Tumbled dark green stone, likely serpentinite or greenstone

Serpentinite (antigorite/lizardite-rich), or chlorite–amphibole greenstone

Green schist (probable chlorite–actinolite schist)

Chlorite–actinolite schist; commonly composed of chlorite, actinolite, epidote, albite, and quartz

Slate

Slate; fine-grained metamorphic rock composed mainly of clay minerals, mica, and quartz

Greenstone

Metabasalt / Chlorite Schist

Nephrite Jade / Pounamu

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

Pyrite

Iron Sulfide (FeS2)

Serpentine-rich metamorphic stone

Serpentinite, chiefly serpentine-group minerals (antigorite, lizardite, or chrysotile) with possible quartz, magnesite, and magnetite

Serpentine

Serpentinite (group of minerals including Antigorite, Lizardite, or Chrysotile) (Mg, Fe)3Si2O5(OH)4

Pyrite

Iron Sulfide (FeS2)

Clear quartz (likely quartzite-like tumbled quartz)

Quartz, silicon dioxide (SiO₂)

Quartzite Pebbles

Quartzite (primarily SiO2)

Serpentinite

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

Rough Gemstone Grains (Mixed Sapphires and Quartz)

Corundum (Al2O3) and Quartz (SiO2)

Weathered greenstone pebble

Metamorphosed mafic rock, commonly metabasalt or greenschist (exact identification requires testing)

Epidote in Quartz

Epidote (Ca2(Al2,Fe3+)3(SiO4)3(OH)) / Quartz (SiO2)

Polished golden-brown banded stone, likely tiger’s eye

Tiger’s eye (quartz with fibrous crocidolite pseudomorphs; SiO₂)

Weathered gray metamorphic rock, likely slate or phyllite

Foliated metapelite; composition commonly quartz, mica, and chlorite

Tiger’s eye

Quartz-rich rock with fibrous crocidolite-derived chatoyant bands; chiefly SiO₂

Greenstone (Celadonite-bearing Volcanic)

Hydrothermally altered basalt or andesite with Celadonite (K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2)

Tumbled dark stone, likely basalt or slate

Basalt (fine-grained plagioclase–pyroxene rock), possibly slate/phyllite

Muscovite Schist

Muscovite Mica Schist (KAl2(AlSi3O10)(OH)2)

Anthracite Coal

Anthracite (Metamorphic Coal)

Chlorite-rich metamorphic rock, likely greenschist

Greenschist; commonly composed of chlorite, actinolite, epidote, albite, and quartz

Gneiss

Banded gneiss; quartz–feldspar–mica rock

Greenish rock with white veins, possibly epidote or chlorite bearing rock with quartz/calcite veins

Altered mafic rock or Epidosite

Anthracite Coal

Anthracite (Carbon-rich metamorphic coal)

Tumbled quartz-rich pebble

Quartz (SiO₂), likely milky quartz or quartzite fragment

Anthracite Coal

Anthracite (Carbon-rich metamorphic rock)

Pink-and-white quartz-rich rock, likely rose quartz in matrix

Quartz (SiO₂), possibly rose quartz hosted in quartzite or feldspathic rock

Greenschist (Greenstone)

Chlorite schist (primarily Chlorite-Epidote-Actinolite-Albite)

Quartz / Quartzite

Silicon Dioxide (SiO2)

Epidote

Epidote; Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

Jadeite Jade

NaAlSi2O6 (Sodium Aluminum Silicate)

Garnet (Spessartine / Almandine)

Fe3Al2(SiO4)3 to Mn3Al2(SiO4)3 (Nesosilicate)

Anthracite Coal

Anthracite (Carbon-rich metamorphic coal)

Tumbled serpentine

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite and carbonate

Weathered greenstone

Metabasalt (greenstone), likely chlorite–actinolite–epidote rock

Rough Sapphire (Corundum)

Corundum (Al2O3)

Micaceous schist (likely biotite schist)

Biotite–quartz–feldspar schist; commonly containing muscovite and/or garnet

Schist

Mica Schist

Red Jasper (Beach Pebble)

SiO2 (Microcrystalline Quartz with Hematite inclusions)

Brown Jasper / River Pebble

Silicon Dioxide (SiO2) - Microcrystalline Quartz