Sedimentary Rock (Metamorphosed)

Anthracite Coal

Anthracite (a variety of coal, predominantly carbon)

Tumbled quartz-rich stone, possibly quartzite

Quartzite (mostly SiO₂), visually similar to chert or weathered quartz sandstone

Weathered iron-stained quartzite or sandstone cobble

Quartzite (quartz, SiO₂), possibly ferruginous sandstone

Sandstone or Quartzite

Sandstone or Quartzite (SiO2 primarily)

Blue-gray stone fragment, possibly slate or fine-grained basalt

Undetermined; appearance is consistent with slate (fine-grained metamorphosed mudstone), but the image is insufficient for reliable identification.

Banded Slate

Slate (Metamorphosed Siltstone/Mudstone)

Mudstone

Argillite / Siliciclastic sedimentary rock

Slate

Slate (Metamorphic rock)

Fine-grained gray-green rock, possibly slate or phyllite

Indeterminate from the image; likely low-grade metamorphosed mudstone (slate/phyllite)

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Rhodonite-bearing rock

Rhodonite (MnSiO₃), likely in a manganese-rich matrix; visual identification is uncertain

Banded Slate Pebble

Metamorphosed Mudstone / Slate

River Cobbles (Quartzite and Sandstone)

Metamorphosed Quartz-rich Sedimentary Rock

River Stone (Quartzite/Chert)

Metamorphosed Quartz-rich Sedimentary Rock

Likely graphite-rich schist

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

Quartz-bearing dark rock, possibly hornfels or basalt

Probable quartz–feldspar rock; exact identification requires testing

Banded metamorphic rock, likely gneiss or metasedimentary slate

Quartz–feldspar–mica gneiss (tentative), possibly containing iron-oxide veins

Greenstone

Metamorphosed Mafic Igneous Rock

Sandstone (Quartzite-rich Pebble)

Arenite (primarily SiO2)

Zebra Jasper

Silicified sedimentary rock (SiO2) with mineral inclusions

Likely biotite-rich schist

Mica schist, likely biotite-rich; exact minerals cannot be confirmed from the photo

Yellow Quartzite (River Pebble)

Quartzite (primarily SiO2)

Quartzite

Metamorphosed Quartz Sandstone

Rounded quartz-rich pebble

Chert or quartzite pebble (indeterminate from image)

Quartz-veined metamorphic rock, likely schist or phyllite

Quartz-bearing mica schist/phyllite; exact identification requires closer examination

Fine-grained, foliated rock (possibly slate or phyllite)

Undetermined; likely slate or phyllite, composed mainly of quartz, mica, and chlorite

Mica-rich schist (tentative)

Mica schist, likely muscovite–biotite schist; exact minerals cannot be confirmed from the image

Claystone / Mudstone

Mudstone (Hydrous aluminum silicate rich rock)

Marble (White)

Metamorphosed Limestone (mainly CaCO3)

Quartzite with Chert inclusions

Metamorphosed Quartz-rich Rock (SiO2)

Rounded quartz-rich pebble

Likely quartzite or quartz-rich sandstone; predominantly quartz (SiO₂)

Pyrite-bearing rock, likely pyrite schist or phyllite

Quartz–mica-rich metamorphic rock with disseminated pyrite (FeS₂); exact rock type cannot be confirmed from the image

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Sandstone or Quartzite pebble

Sandstone (Quartz arenite) or Quartzite

Veined Limestone (or Quartz-Veined Slate/Shale)

Metamorphosed Sedimentary Rock with Calcite/Quartz Veins

Quartzite (River Pebble)

Metamorphosed Sandstone (SiO2)

Likely greenstone (metamorphosed basalt)

Metabasalt; commonly composed of chlorite, actinolite, epidote, and albite

Rounded gray pebble

Uncertain; likely quartz-rich sandstone, quartzite, or graywacke

Brown quartz-rich pebble (likely chert or weathered quartzite)

Quartz (SiO₂), possibly microcrystalline quartz/chert or quartzite

Likely muscovite-bearing mica schist

Mica schist, composed mainly of quartz and mica (muscovite and/or biotite)

Biotite-rich schist (probable)

Mica schist, rich in biotite (K(Mg,Fe)₃AlSi₃O₁₀(OH,F)₂); exact identification is uncertain from the image alone.

Riverstone (likely Gray Slate or Siltstone)

Metamorphosed fine-grained sedimentary rock (Argillite/Slate)