Metamorphic Or Sedimentary Depending On Local Grade

Mica-rich Sandstone or Micaceous Schist Weathering

Micaceous Schist (Muscovite-Quartz composition)

Gneiss

Gneiss (High-grade metamorphic rock)

Rough Garnet (Almandine)

Almandine Garnet (Fe3Al2(SiO4)3)

Gneiss (specifically Pink Gneiss)

Gneiss (high-grade regional metamorphic rock)

Dark gray slate (possibly argillite or shale)

Slate, a low-grade metamorphic rock derived mainly from shale; composition commonly quartz, illite/muscovite, chlorite, and clay minerals

Likely amphibolite

Amphibolite, composed chiefly of hornblende and plagioclase

Slate or thinly bedded shale

Slate; primarily fine-grained mica/clay minerals and quartz

Gneiss

Gneiss

Garnet in Matrix (likely Almandine in Quartz/Mica Schist)

Almandine Garnet (Fe3Al2(SiO4)3) in Quartz-Feldspar host rock

Lapis Lazuli (polished cabochon)

Lazurite-rich metamorphic rock (approx. Na6Ca2Al6Si6O24(SO4,S,Cl)2)

Gneiss

Quartz–feldspar–mica gneiss

Weathered schist or phyllite

Mica schist/phyllite; quartz–mica-rich foliated metamorphic rock

Greenschist

Chlorite Schist (Greenschist Facies)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Biotite Schist

Metamorphic Rock (Schist)

Greenstone

Chlorite schist or metabasalt depending on specific composition

Banded amphibolite (likely hornblende schist)

Amphibolite; chiefly hornblende + plagioclase, with possible biotite and garnet

Smoky quartz-bearing feldspar pegmatite

Quartz (SiO₂) with feldspar, likely a granitic pegmatite

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Graphite-rich schist (likely graphite ore)

Graphite-bearing schist; predominantly graphitic carbon (C) with mica, quartz, and possible feldspar

Likely amphibolite

Amphibolite, composed chiefly of hornblende (amphibole) and plagioclase feldspar

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Greenstone or Metabasalt

Metabasalt / Chlorite Schist

Feldspar-rich Quartzite

Meta-arkose (Quartz-Feldspar Quartzite)

Likely graphite-rich schist

Graphite-bearing schist, composed mainly of graphite with possible mica and quartz

Milky Quartz with Iron Inclusions

Quartz (Silicon Dioxide, SiO2)

Weathered metamorphic schist

Mica schist, likely muscovite–biotite schist with quartz and feldspar

Likely weathered sandstone or metasandstone

Quartz-rich sandstone (possibly weakly metamorphosed metasandstone)

Conglomerate

Conglomerate (clastic sedimentary rock)

Epidote

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

Rounded greenstone cobble

Likely greenschist or altered basalt; composition commonly chlorite, epidote, actinolite, albite, and quartz

Quartz-rich rock, likely quartzite

Quartzite; predominantly crystalline SiO₂, with minor iron-oxide staining and possible feldspar/mica

Yellow Quartzite (Onyx Pebble)

Silicon Dioxide (SiO2) - Quartzite

Magnetite (Charnockite Regional Variation)

Magnetite (Fe3O4)

Banded gneiss

Felsic biotite–quartz–feldspar gneiss

Almandine Garnet in Matrix

Almandine (Fe3Al2(SiO4)3)

Ironstone / Weathered Hematite

Iron oxide-rich sedimentary rock with Goethite/Hematite

Pebble

Lithified rock fragment / Sedimentary clast

Quartz with Schist Matrix

Crystalline Silicon Dioxide (SiO2) in micaceous schist

Ferruginous Conglomerate

Conglomerate with Iron-Oxide Matrix (SiO2 + Fe2O3/FeO(OH))

Weathered quartz-rich rock, likely quartzite or silicified sandstone

Quartzite; predominantly microcrystalline to granular SiO₂, possibly with iron-oxide impurities

Slate

Slate; predominantly fine-grained phyllosilicates (muscovite/illite, chlorite) with quartz and feldspar