Sedimentary Rock (Metamorphosed)

Rounded granite or granitic gneiss cobble

Granite–gneiss, chiefly quartz, feldspar, and mica

Puddingstone

Conglomerate (Gowganda Formation)

Weathered quartz-rich pebble

Quartzite or silicified sandstone; predominantly microcrystalline quartz (SiO₂)

Iron-stained quartzite or quartz-rich metamorphic rock

Quartzite, predominantly SiO₂, with iron-oxide coatings (goethite/hematite)

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

Quartzite (dominantly SiO₂), with hematite/goethite surface staining

Jasper with Quartz Veining

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Dark metamorphic rock, likely schist or phyllite

Quartz–mica schist/phyllite; chiefly quartz, mica, and feldspar

Weathered granite or granitic gneiss block

Granite, chiefly quartz, feldspar, and mica; possibly gneiss if the visible banding is structural

Rounded quartz-rich pebble

Likely quartz sandstone or quartzite; visual identification is uncertain

Greenstone (Prase / Metavolcanic)

Metamorphosed volcanic rock (Greenstone)

Greenstone

Metabasalt / Metamorphosed Igneous Rock

Quartz-rich rock fragment, possibly milky quartz or quartzite

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

Weathered sulfide-bearing metamorphic rock (likely pyrite- or chalcopyrite-rich schist)

Quartz–mica schist with iron sulfides; possible pyrite (FeS₂) and chalcopyrite (CuFeS₂)

Tumbled gray quartz-rich stone, possibly quartzite or chert

Likely quartzite (microcrystalline SiO₂), though the photograph cannot distinguish it confidently from gray chert or silicified limestone

Possible shale or slate fragment

Fine-grained clay-rich rock; possibly slate (low-grade metamorphosed shale)

Quartz-rich metamorphic rock, likely mica schist

Mica schist; chiefly quartz (SiO₂) and mica, likely muscovite/biotite, with possible feldspar

Pelitic schist fragment, possibly garnet-mica schist

Muscovite–biotite schist with quartz; possible almandine garnet

Rounded gray-brown cobble, likely weathered sandstone or quartzite

Tentatively quartz-rich sandstone (SiO₂-dominated); exact identification requires hardness and acid tests

Unakite

Unakite (metamorphosed granitic rock)

Greenstone Pebbles (Basalt/Diabase)

Metamorphosed Mafic Rock (Greenstone)

River Stone (Quartzite/Siltstone)

Metamorphosed Siliciclastic Rock (SiO2)

Greenstone with Quartz Veining

Metamorphosed Mafic Igneous Rock

Greenstone

Greenschist (Metamorphosed Mafic Rock)

Greenstone / Greenschist

Greenschist (metamorphosed mafic rock)

Greenstone / Greenschist

Greenschist (metamorphosed mafic rock)

Greenstone (Diabase or Metabasalt)

Metamorphosed Mafic Igneous Rock

Greenstone / Quartzite Pebble

Metamorphosed Quartz-rich Rock

Light-colored sandstone or quartzite

Quartz-rich sandstone; possibly weakly metamorphosed quartzite

Likely fuchsite-bearing quartzite (green quartzite)

Quartz-rich metamorphic rock with green chromium-rich muscovite (fuchsite); exact identification is uncertain from the image

Weathered quartz-rich pebble

Likely quartzite or quartz-bearing sandstone; identification is uncertain from the photograph alone

Banded gneiss pebble

Gneiss, commonly quartz–feldspar–mica gneiss

Quartz-bearing granite or granitic gneiss

Granite; chiefly quartz (SiO₂), feldspar, and dark mica/amphibole

Weathered layered metamorphic rock, likely schist or phyllite

Micaceous quartz–feldspar schist/phyllite; exact identification requires a fresh surface and testing

Graphite-bearing metamorphic rock (probable graphite schist)

Graphite schist; predominantly quartz–mica–graphite, with possible feldspar and sulfide minerals

Rounded river pebble, likely quartz-rich sandstone or fine-grained quartzite

Indeterminate quartz-rich lithic clast; likely quartz sandstone (SiO₂-rich) or quartzite

Likely graphite-rich schist (possibly galena-bearing metamorphic rock)

Graphite schist; chiefly quartz–mica with graphite (identification uncertain from photograph)

Weathered river pebble, likely quartz-rich sandstone or iron-stained quartzite

Provisional identification: quartz-rich sandstone/quartzite; exact composition cannot be confirmed from the image

Weathered quartz-rich metamorphic rock, likely quartzite or gneiss

Quartzite/gneiss; chiefly quartz (SiO₂) with feldspar and mica/iron oxides

Iron-rich quartzite or ferruginous metamorphic rock

Ferruginous quartzite, likely hematite/goethite-bearing quartzite; SiO₂ with Fe₂O₃/FeO(OH)

Weathered sandstone or quartzite cobble

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

Weathered iron-rich metamorphic rock (probable amphibolite or schist fragment)

Likely hornblende–plagioclase amphibolite with biotite/chlorite alteration; exact identification requires testing

Pyrite-bearing metamorphic rock (likely schist or gneiss)

Pyrite (FeS₂) in a quartz–mica-rich host rock