Sedimentary Rock (Metamorphosed)

Serpentinized ultramafic rock (likely serpentinite)

Serpentinite; chiefly serpentine-group minerals, with possible magnetite, olivine, pyroxene, and talc

Quartz-rich rock, likely milky quartz

Quartz (silicon dioxide, SiO₂), possibly a quartzite fragment

White quartz-rich rock, likely quartzite or silicified sediment

Quartzite (mostly quartz, SiO₂); possibly silicified limestone or chert

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Likely slate or fine-grained metamorphic rock

Slate/phyllite; predominantly fine-grained mica, chlorite, and quartz

Slate

Slate (Metamorphic Rock)

Quartzite Pebble (with possible inclusion)

Metamorphosed Quartz Sandstone (SiO2 with impurities)

Weathered granite or granitic gneiss

Quartz–feldspar–mica aggregate; likely granite, possibly foliated gneiss

Vein-bearing sandstone or quartzite cobble

Quartz-rich sandstone with white quartz veins; possibly metamorphosed to quartzite

Quartz-rich rock, possibly milky quartz or quartzite

Quartz (SiO₂), potentially quartzite if the grains are fused

Quartzite Pebble

Quartzite (Metamorphosed Quartz Sandstone, SiO2)

Quartz-rich granite or granitic gneiss cobble

Granite; primarily quartz, feldspar, and mica, possibly with gneissic deformation

Slate or shale fragment

Slate; predominantly clay minerals, mica, and quartz (low-grade metamorphosed shale)

Banded Slate (Sedimentary Pebble)

Slate (Metamorphosed Shale or Mudstone)

Rounded quartz-rich pebble

Probable arkosic sandstone or weathered quartzite; exact identification is uncertain from the image

Rounded quartz-rich pebble

Likely quartzite or quartz-rich sandstone pebble; SiO₂-dominant

Tumbled quartz-rich rock, likely granite or granitic gneiss

Granite/granitic gneiss; chiefly quartz (SiO₂), feldspars, and minor mica/amphibole

Graphite-bearing schist (probable)

Graphite schist; primarily quartz, mica, and graphite (carbon)

Iridescent schist or phyllite

Micaceous quartz-rich schist/phyllite, likely containing muscovite or chlorite

Likely weathered mica-rich rock fragment

Probable schist, composed mainly of quartz, feldspar, and mica

Weathered igneous rock fragment, possibly granite or granitic gneiss

Indeterminate; likely quartz–feldspar–mica aggregate (granite), possibly foliated gneiss

Quartzite with Quartz Vein

Metamorphosed Quartz-rich Arenite (SiO2)

Rounded quartz-rich river pebble

Feldspathic quartz sandstone or quartzite pebble (exact identification requires testing)

Likely weathered sandstone or quartzite

Quartz-rich sandstone (SiO₂-dominant); possibly metamorphosed to quartzite

Likely blue-gray stone, possibly slate or basalt

Indeterminate; candidates include slate (fine-grained metamorphic rock) or basalt (mafic igneous rock)

Serpentinized ultramafic rock (likely serpentinite)

Serpentinite; chiefly serpentine-group minerals Mg₃Si₂O₅(OH)₄, with magnetite, olivine, and pyroxene remnants

Pyrite-bearing metamorphic rock (probable pyrite schist)

Schist containing pyrite (FeS₂), with probable quartz and mica

Tumbled granite or granitic gneiss

Granite, typically quartz + feldspar + mica; possibly foliated granitic gneiss

Blue quartzite or blue schist (likely quartzite)

Quartz-rich metamorphic rock; predominantly SiO₂, possibly with blue amphibole or dumortierite

Iron-stained quartz-rich rock, likely weathered quartzite

Quartzite (dominantly quartz, SiO₂), with iron-oxide minerals such as hematite/goethite

Iron-stained quartz-rich rock, likely quartzite or silicified breccia

Quartz (SiO₂), possibly quartzite with limonite/goethite iron oxides

Quartz-rich iron-stained rock, likely quartzite or quartz vein material

Quartz (SiO₂), with iron oxides/hydroxides such as hematite and goethite

Serpentinized ultramafic rock with magnesite

Serpentinite, chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), with likely magnesite (MgCO₃) and minor chromite/magnetite

Slate or fine-grained shale

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

Limestone

Calcium Carbonate (CaCO3)

Polished greenstone (likely serpentinite or chlorite-rich schist)

Serpentinite/chlorite-rich ultramafic metamorphic rock; composition commonly dominated by serpentine-group minerals, chlorite, magnetite, and minor amphibole or pyroxene

Weathered gray stone, likely granite or gneiss

Probable granitic rock; exact identification is uncertain from the image

Granite or granitic gneiss pebble

Quartz–feldspar–mica aggregate; possibly banded gneiss

Rounded granite or granitic gneiss cobble

Granite, chiefly quartz, potassium feldspar, plagioclase, and biotite/hornblende

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly crystalline SiO₂, with possible iron-oxide and dark mica/mineral inclusions

Iron-rich quartzite or weathered ironstone pebble

Quartzite, chiefly SiO₂, with iron-oxide minerals (hematite/goethite)

Weathered quartz-rich rock, possibly sandstone or quartzite

Indeterminate; likely quartz sandstone (SiO₂-rich), possibly weakly metamorphosed quartzite