Industrial Byproduct (Anthropogenic Rock)

Tumbled brecciated jasper (likely)

Jasper, an opaque microcrystalline variety of quartz (SiO₂), with pale quartz/chalcedony veins

Sandstone

Arenite (SiO2 principal component)

Likely milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Unidentified weathered rock fragments

Likely mixed quartz- and feldspar-bearing silicate material; exact identification requires testing

Granite

Phaneritic Igneous Rock (composed of quartz, alkali feldspar, and plagioclase)

Quartz Pebble

Silicon Dioxide (SiO2)

Granitic Pegmatite

Granite Pegmatite (coarse-grained intrusive igneous rock)

Ferruginous Sandstone (Gerrit)

Arenite with Iron Oxide cementation

Quartzite Pebble

Quartzite (primarily SiO2)

Sandstone

Arenite (SiO2 primarily)

Quartzite

Quartzite (SiO2)

Basalt with Porphyritic Texture

Porphyritic Basalt

Possible pink quartz specimen in a dark matrix

Uncertain from the image; possibly rose quartz (SiO₂) attached to a dark host rock

Painted Sandstone Cobble

Clastic Sedimentary Rock (Sandstone base)

Crushed Limestone

Sedimentary Calcium Carbonate (CaCO3)

Diamond jewelry setting

Diamond (crystalline carbon, C) in a metal setting; the small stones’ identity is not visually confirmable

River Stone (likely Siltstone or fine-grained Quartzite)

Sedimentary clastic rock containing SiO2 and iron oxides

Quartz Vein in Host Rock

Quartz (SiO2) in metamorphic host rock (likely schist or phyllite)

Asphalt Concrete

Bituminous conglomerate

Pumice

Pumice (a highly vesicular, silicic volcanic rock)

Quartzite

Metamorphic rock primarily composed of Quartz (SiO2)

Water-worn pebble, likely fine-grained volcanic rock

Unidentified mafic volcanic rock; possibly andesite or basalt

Basalt River Stone

Basalt

Small banded metamorphic rock fragment

Indeterminate foliated metamorphic rock; possibly mica schist or gneiss

Schist

Mica Schist

Quartz vein in weathered host rock

Likely milky quartz (SiO₂) with iron-oxide staining and altered host rock; exact rock cannot be determined from the photo

Iron-rich meteorite candidate

Undetermined; possible stony-iron or iron meteorite, commonly kamacite–taenite (Fe–Ni)

Rounded gray pebble, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; commonly plagioclase with pyroxene and/or olivine

Basalt (Vesicular)

Vesicular Basalt

Banded Gneiss

Gneiss

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated Iron Oxide)

Quartz Pebble (Water-worn Quartzite)

Silicon Dioxide (SiO2)

Likely black river pebble

Undetermined; possibly a dark mafic rock such as basalt or andesite

Tumbled agate (likely)

Microcrystalline quartz, SiO₂; agate is banded chalcedony

Coal

Bituminous Coal / Anthracite

Schist

Mica Schist

Uncertain small tan mineral/rock fragment

Indeterminate from image; possibly feldspar-rich rock or calcite

Serpentine

Serpentine subgroup (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4

Weathered brown rock fragment, possibly iron-rich sandstone or altered basalt

Indeterminate; likely an iron-oxide–stained silicate rock

Unidentified pale mineral or rock specimen

Indeterminate; image quality prevents reliable mineral identification

Quartzite

Quartzite (primarily SiO2)

Granite

Granite (Felsic Plutonic Rock)