Metamorphic (Low Grade)

Greenschist

Greenschist facies metamorphic rock; commonly chlorite–actinolite–epidote schist

Epidote in Granite Gneiss

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

Serpentine

Antigorite-Lizardite-Chrysotile (Mg3Si2O5(OH)4)

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

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 / Serpentinite

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

Emerald

Beryl (Be3Al2(SiO3)6) colored by Chromium and/or Vanadium

Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Anthracite Coal

Anthracite (Carbon C)

Emerald

Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities

Tumbled jasper or chert (tentative)

Microcrystalline quartz, SiO₂, likely opaque chalcedony/jasper

Likely gneiss

Gneiss, composed chiefly of quartz, feldspar, and mica/amphibole

Serpentine

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

Anthracite Coal

Anthracite (Carbon-rich metamorphic coal)

Clear quartz (likely quartzite-like tumbled quartz)

Quartz, silicon dioxide (SiO₂)

Banded gneiss

Gneiss, commonly quartz–feldspar–biotite gneiss

Weathered mica-rich schist

Mica schist, chiefly muscovite/biotite with quartz and feldspar

Pyrite

Iron Sulfide (FeS2)

Foliated shale or slate fragment

Fine-grained phyllite/slate, composed mainly of clay minerals, mica, and quartz

Polished tiger’s-eye / iron-rich quartzite

Quartz (SiO₂), commonly pseudomorphic tiger’s-eye with limonite/goethite and remnants of crocidolite fibers

Dark metamorphic pebble, likely slate or phyllite

Slate/phyllite; chiefly fine-grained mica and quartz, with possible chlorite and graphite

Greenstone (or River-tumbled Basalt / Greywacke with Epidote)

Metabasalt / Greenschist facies rock

Greenstone / River Siltstone

Metasedimentary Greenstone (Chlorite-rich Siltstone)

Greenstone

Greenschist (metamorphosed mafic igneous rock)

Likely biotite-rich schist with a quartz/feldspar inclusion

Mica schist; chiefly quartz (SiO₂), feldspar, and biotite mica

Tumbled dark stone, likely basalt or slate

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

Pyrite

Iron Sulfide (FeS2)

Rough Gemstone Grains (Mixed Sapphires and Quartz)

Corundum (Al2O3) and Quartz (SiO2)

Lapis Lazuli (Low Quality/Rough)

Lapis Lazuli (comprised of Lazurite, Calcite, and Pyrite)

Greenstone, likely serpentinite

Serpentinite; predominantly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), possibly with chlorite, talc, magnetite, or antigorite

Serpentinite

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

Weathered quartz-bearing sandstone or quartzite

Quartzite (SiO₂-rich), possibly weakly metamorphosed sandstone

Rhodonite-bearing metamorphic rock

Rhodonite (MnSiO₃) in manganese-rich schist/gneiss, possibly with quartz and amphibole

Weathered iron-rich rock, possibly garnet schist or mica schist

Foliated metamorphic rock; likely mica schist with iron oxides and quartz, but exact identification is uncertain from the image

Quartzite pebble (likely)

Quartzite; predominantly microcrystalline quartz (SiO₂)

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)

Eclogite

Eclogite

Banded calcite (likely polished limestone/marble fragment)

Calcite, CaCO₃; probable banded calcitic marble

Blue-gray metamorphic rock, possibly slate or phyllite

Likely quartz–mica-rich phyllite/slate; exact identification requires testing

Calcite-rich marble or limestone

Calcite (CaCO₃), likely recrystallized limestone (marble)