Sedimentary Rock (Metamorphosed)

Weathered quartz-bearing rock fragment

Indeterminate; likely quartz-rich granite, gneiss, or pegmatitic rock

Pyrite-bearing rock, likely schist or quartzite

Pyrite (FeS₂) in a foliated silicate matrix, possibly mica schist

Quartz-rich gneiss or quartzite

Quartz–feldspar–mica metamorphic rock; exact identification requires a fresh surface and tests

Biotite-bearing granite or granitic gneiss

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

Quartz-rich rock, possibly milky quartz or quartzite

Quartz (silicon dioxide, SiO₂); if granular and foliated, likely quartzite

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Weathered red granite or granitic gneiss cobble

Granite, chiefly quartz, feldspar, and mica; possibly foliated granitic gneiss

Brecciated quartzite (likely iron-stained quartz vein material)

Quartzite; predominantly quartz (SiO₂), with dark iron/manganese-oxide or mica-rich seams

Quartzite

Quartzite (mostly SiO2)

Tumbled serpentine-rich altered rock

Serpentinite, likely antigorite/lizardite with accessory carbonate, quartz, or iron oxides

Weathered granite or granitic gneiss

Granite; chiefly quartz, feldspar, and mica (possibly gneissic if foliation is confirmed)

Dark mica-rich metamorphic rock, likely schist

Mica schist; commonly quartz–biotite ± muscovite schist

Dark gray fine-grained rock, possibly slate

Slate (fine-grained metamorphosed mudstone; identification uncertain from image)

Weathered greenish-gray rock fragment, likely chlorite-rich schist

Tentatively chlorite schist; exact identification requires closer examination

Likely basaltic rock

Fine- to medium-grained mafic igneous rock, probably basalt or metamorphosed basalt (metabasalt)

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Vein-bearing sandstone or quartzite cobble

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

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Polished granite or gneiss cobble

Banding of quartz, feldspar, mica, and ferromagnesian minerals; likely gneiss, possibly weathered granite

Tumbled granite or granitic gneiss pebble

Granite/granitic gneiss, chiefly quartz, feldspar, and dark biotite or amphibole

Pegmatitic gneiss with a quartz–feldspar vein

Quartz–feldspar-rich gneiss, locally cut by a granitic pegmatite vein

Iron-rich quartzite or ironstone

Ferruginous quartzite; predominantly quartz (SiO₂) with hematite/goethite (Fe₂O₃/FeO(OH))

Sodalite

Sodalite (Na8Al6Si6O24Cl2)

Zebra Marble

Metamorphosed Alabaster/Limestone (CaCO3)

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

Indeterminate; probable quartz (SiO₂)-rich sandstone/quartzite with iron-oxide staining

Unidentified gray weathered rock

Possibly weathered granite or granitic gneiss; exact identification requires a fresh surface and tests

Quartzite (Quartz Pebble)

Quartzite (SiO2 with iron oxide inclusions)

Weathered granite or granitic gneiss

Granite; primarily quartz (SiO₂), feldspars, and biotite/muscovite mica

Weathered rounded stone, likely quartz-rich sandstone or granitoid

Indeterminate feldspathic quartz rock; possibly weathered granite or granitic gneiss

Weathered granite or granitic gneiss

Granite: quartz, feldspar, and mica; possibly weakly foliated gneiss

Feldspar-rich igneous rock, likely granite or gneiss fragment

Granite-like quartz–feldspar rock; exact identification is uncertain from the blurred image

Banded Quartzite

Metamorphosed Quartz Sandstone / Quartzite

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Iron-stained quartz-rich rock, possibly jasperized quartz or quartzite

Mostly SiO₂ quartz with iron oxides/hydroxides (hematite, goethite) and possible clay or feldspar impurities

Biotite-bearing granite or granitic gneiss

Granite; primarily quartz (SiO₂), feldspar, and biotite mica

Quartzite with Quartz Veining

Metamorphosed Quartz-rich Sandstone (SiO2)

Likely gray granite or gneiss fragment

Granite: quartz, feldspar, and mica; possibly banded gneiss if foliation is present

Pyrite-bearing dark metamorphic rock, likely schist or hornfels

Quartz–feldspar–mica matrix with pyrite (FeS₂); exact identification requires testing

Likely mica-rich schist

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