Unknown (Likely Sedimentary Or Metamorphic)

Rhodonite-bearing gneiss

Manganese-rich biotite gneiss with rhodonite (MnSiO₃)

Likely weathered quartz-bearing rock (uncertain identification)

Possibly quartz-rich granite or granitic aplite; exact identification requires a clearer, larger image and tests

Tumbled banded gneiss or amphibolite

Banded metamorphic rock, likely quartz–feldspar–biotite gneiss with amphibole

Iron-rich quartzite or weathered ironstone

Quartzite, chiefly SiO₂, with iron-oxide minerals such as hematite/goethite

Weathered greenstone

Metamorphosed mafic rock, commonly chlorite–actinolite schist or altered basalt

Likely biotite-rich schist

Mica schist, chiefly quartz–biotite ± feldspar; exact identification requires testing

Quartz (likely a form of massive or vein quartz)

Quartz (SiO₂)

Mica schist

Muscovite–biotite schist, composed mainly of mica and quartz

Weathered metamorphic rock, possibly schist or gneiss

Indeterminate; likely quartz–feldspar–mica rock, potentially greenschist or gneiss

Clear Quartz

Silicon Dioxide (SiO2)

Iron-Stained Quartzite

Recrystallized Meta-Quartzite (primarily SiO2)

Marble

Recrystallized Calcite Rock (CaCO3)

Fossil shell fragment, likely bivalve or brachiopod

Indeterminate fossilized mollusk/brachiopod; commonly calcite (CaCO₃)

Quartz (Milky/Iron-stained)

Silicon Dioxide (SiO2)

Banded metamorphic rock, likely mica schist or gneiss

Mica schist/gneiss, chiefly quartz, feldspar, biotite and muscovite

Purple-gray shale or slate fragment

Argillite/slate, chiefly compacted clay minerals with quartz and mica

Quartzite River Cobble

Quartzite (dominated by SiO2)

Mixed rounded gravel and weathered rock fragments

Polymictic alluvial or glacial gravel; composition appears to include basaltic, quartz-rich, and feldspathic clasts

Polished banded stone, likely gneiss or metasedimentary rock

Banded gneiss (quartz–feldspar–mica assemblage; exact identification requires testing)

Weathered sandstone or iron-stained quartzite fragment

Quartz-rich sandstone (SiO₂), possibly ferruginous sandstone; exact identification requires testing

Biotite-bearing metamorphic rock, likely schist

Mica schist; chiefly quartz, feldspar, and biotite mica

Rounded quartz-rich cobble, possibly quartzite

Quartzite (mostly microcrystalline quartz, SiO₂); identification tentative from the photograph

Small translucent quartz fragment

Quartz (SiO₂), possibly milky or near-colorless quartz

Quartzite

Quartzite; predominantly microcrystalline quartz (SiO₂)

Black-and-white veined stone, likely marble or calcite-veined metamorphic rock

Probable calcite marble: predominantly recrystallized calcite (CaCO₃) with dark graphite-, mica-, or amphibole-rich minerals

Polished jasper–quartzite river pebble

Silicified metasedimentary rock, chiefly microcrystalline quartz (SiO₂) with iron-oxide staining

Rounded quartz-rich pebble, likely quartzite or chert

Quartzite (mostly microcrystalline SiO₂); exact identification requires hardness and acid tests

Likely raw garnet fragment

Garnet-group silicate, commonly almandine (Fe₃Al₂Si₃O₁₂)

Weathered iron-rich stone, possibly limonite-bearing sandstone or laterite

Goethite–hematite/limonite mixture; exact identification requires testing

Quartzite (River Cobble)

Quartzite (primarily SiO2)

Weathered fossil shell fragment

Likely a fossilized bivalve or gastropod fragment; exact taxon cannot be determined from one view

Tumbled orange jasper/quartzite pebble

Jasper, microcrystalline quartz (SiO₂), likely iron-oxide colored

Rounded quartz-rich pebble, likely quartzite or quartz sandstone

Quartzite (mostly SiO₂), possibly ferruginous quartz sandstone

Rounded quartz-rich cobble, likely quartzite

Quartzite; predominantly SiO₂ (recrystallized quartz)

Polished hematite sphere

Hematite (Fe₂O₃), likely a polished specular or massive variety

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Rounded brown river pebble, likely sandstone or iron-rich quartzite

Probable ferruginous sandstone; possibly quartzite (SiO₂-rich)

Tumbled garnet-bearing metamorphic rock (probable garnet schist)

Garnet schist; chiefly quartz, mica, feldspar, and almandine garnet (Fe₃Al₂Si₃O₁₂)

Weathered iron-stained quartzite or chert nodule

Siliceous rock composed chiefly of microcrystalline quartz (SiO₂), with iron-oxide staining and possible clay/minor carbonate minerals

Gneiss (likely)

Gneiss

Banded gneiss or banded metamorphic rock

Gneiss, likely quartz–feldspar–biotite gneiss

Green Aventurine

Aventurine Quartz (SiO2 with inclusions of Fuchsite)