Sedimentary Rock (Metamorphosed)

Weathered garnet-bearing rock (possibly garnet schist)

Garnet-bearing mica schist; likely almandine garnet (Fe₃Al₂(SiO₄)₃) with mica and quartz

Rounded river pebble, likely quartz-rich sandstone or weathered quartzite

Indeterminate; probable quartz (SiO₂)-rich clastic rock

Likely weathered sandstone or metasandstone

Quartz-rich sandstone (possibly weakly metamorphosed metasandstone)

Weathered sandstone or metasedimentary rock

Quartz-rich sandstone; possibly weakly metamorphosed quartzite

Weathered iron-rich sandstone or ferruginous quartzite

Ferruginous sandstone; possibly hematite/goethite-cemented quartzite

Weathered quartz-rich rock, possibly chert or quartzite

Indeterminate; likely microcrystalline quartz (SiO₂), possibly quartzite or chert

Greenstone (Greywacke or Nephrite Jade variant)

Metamorphosed mafic igneous or sedimentary rock (e.g., Actinolite-Chlorite Schist)

Weathered quartz-rich rock, likely quartzite

Quartzite (mostly SiO₂), possibly quartz-rich sandstone or milky quartz vein material

Coarse-grained granite or granitic gneiss

Granite; predominantly quartz, potassium feldspar, plagioclase, and dark biotite/hornblende

Rounded river cobble, likely quartz-rich sandstone or quartzite

Indeterminate quartz-rich clastic rock; probable sandstone (SiO₂-rich)

Jasper / Quartzite pebble

Silicon dioxide (SiO2) with iron impurities

Quartz-veined basalt or mafic schist

Basaltic rock dominated by plagioclase–pyroxene minerals, with milky quartz/calcite veins

Quartzite

SiO2 (Metamorphosed Sandstone)

Quartzite

SiO2 (Metamorphosed Sandstone)

Weathered schist or foliated metamorphic rock

Mica-quartz schist, tentatively; mineral composition likely quartz, mica, and feldspar

Micaceous iron-rich metamorphic rock (probable schist)

Biotite–muscovite quartz schist, possibly containing hematite or sulfide minerals

Polished Marble (likely Carrara-type with Iron oxides)

Metamorphosed Carbonate (CaCO3)

Quartzite

Metamorphosed Quartz Sandstone

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Amphibolite (likely)

Amphibolite, composed mainly of hornblende-group amphibole and plagioclase feldspar

Quartz-bearing reddish metamorphic rock, possibly ferruginous quartzite or jasper vein

Quartz (SiO₂) with iron oxides; likely quartzite or iron-rich jasper

Quartzite

Metamorphosed Quartz Sandstone

Weathered gray sandstone or fine-grained metamorphic rock

Likely quartz-rich sandstone (quartz arenite), possibly weakly metamorphosed metasandstone

Weathered granite or granitic gneiss

Granite; primarily quartz, feldspar, and mica (possibly gneiss if the faint banding is structural)

Biotite-bearing granitic gneiss

Quartz–feldspar–biotite gneiss; composition approximately quartz + plagioclase/K-feldspar + biotite ± amphibole

Water-worn quartzite or sandstone cobble

Quartzite (predominantly SiO₂), possibly quartz-rich sandstone

Muscovite mica schist

Muscovite-rich schist; predominantly muscovite mica (KAl₂(AlSi₃O₁₀)(OH)₂) with quartz and minor iron oxides

Quartzite Pebble

Metamorphosed Quartz (SiO2)

Shale or slate fragment

Fine-grained phyllosilicate rock, likely slate (metamorphosed shale)

Slate or strongly foliated schist

Metamorphosed shale; commonly muscovite–quartz–chlorite schist or slate

Banded Sandstone or Quartzite Pebble

SiO2 (dominant) with impurities

Marble

Metamorphosed Limestone (CaCO3)

Serpentine (likely greenstone)

Serpentine-group minerals, chiefly antigorite, lizardite, and chrysotile; commonly with magnesite or magnetite

Weathered quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂), possibly quartzite with iron-oxide staining

Dark foliated metamorphic rock, likely slate or phyllite

Fine-grained metamorphosed mudstone; exact identification is uncertain from the photograph

Likely anthracite coal fragments

Anthracite; predominantly carbon (C), with minor mineral ash

Quartzite Pebble

Metamorphosed Quartz Sandstone

Quartzite Pebble

Si02 (Metamorphosed Sandstone)

Quartzite Pebble

Metamorphosed Sandstone (SiO2)

Quartzite

Metamorphosed Sandstone (SiO2)

Greenstone, likely altered basalt (possibly serpentinite)

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

Quartzite

Metamorphosed Quartz Sandstone