Industrial Byproduct (Anthropogenic Rock Like Material)

Tektite

Impactite (Natural Silicate Glass)

Quartzite

Metamorphic Quartzite (SiO2)

Asphalt (Road Aggregate)

Bituminous conglomerate

Ruby (Raw Corundum)

Al2O3 (Aluminum Oxide)

Sandstone (Ferruginous)

Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 staining)

Siltstone with flute casts or scratch marks

Clastic Sedimentary Rock (Siltstone/Fine-grained Sandstone)

Polished citrine quartz point

Quartz, silicon dioxide (SiO₂), yellow-orange variety commonly sold as citrine; possibly heat-treated amethyst

Chert (specifically Jasper)

Silicon dioxide (SiO2) with iron oxide inclusions

Scoria

Scoriaceous Basalt

Weathered quartzite cobble

Quartzite, predominantly crystalline SiO₂

Vuggy Chert / Silicified Limestone

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Granite Cobble

Granite

Red Sandstone

Sandstone (principally Quartz, SiO2, with Iron Oxide hematite cement)

Biotite-rich granite or granitic gneiss

Granite; quartz–feldspar–biotite assemblage

Moss Agate / Chalcedony

Silicon Dioxide (SiO2)

Pink Chalcedony (Agate/Jasper blend)

Silicon Dioxide (SiO₂)

Sandstone (Banded)

Arenite

Sandstone

Arenite (Secondary classification based on grain size)

Green Chert (Jasper)

Silicon Dioxide (SiO2)

Chert (Flint)

Microcrystalline quartz (SiO2)

Chert Pebble

Microcrystalline Quartz (SiO2)

Mica Schist

Schist (muscovite/biotite rich regional metamorphic rock)

Tumbled black stone, likely basalt or obsidian

Uncertain; likely fine-grained basalt (plagioclase–pyroxene) or dark volcanic glass (obsidian)

Sandstone

Arenite (SiO2 based)

Chert (Yellow Jasper)

Microcrystalline Quartz (SiO2)

Granitic Pegmatite

Coarse-grained Granite (KAlSi3O8 + SiO2)

Carved serpentine wing sculpture

Serpentine-group rock, chiefly antigorite/lizardite: Mg3Si2O5(OH)4

Granite

Granite

Brecciated quartz-rich rock, possibly silicified breccia

Silica-rich breccia; chiefly microcrystalline quartz (SiO₂), with possible calcite and iron-oxide staining

Quartzite

Quartzite (SiO2)

Quartz Druzy (on Calcedony/Quartz base)

Silicon Dioxide (SiO2)

Serpentinite

Serpentinite (Hydrated magnesium iron phyllosilicate)

Chert (Jasper/Limonitic Chert)

Silicon dioxide (SiO2)

Chert (Sedimentary Rock)

Silicon Dioxide (SiO2)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Quartz (Double-Terminated)

Silicon Dioxide (SiO2)

Pumice

Pumice (a highly vesicular volcanic rock)

Diamond

C (Carbon)

Agate

Silicon Dioxide (Chalcedony), SiO2

Sandstone

Arenite (SiO2 based clastic rock)

Chert (and Flint)

Cryptocrystalline Quartz (SiO2)

Chert (Yellow Jasper)

Microcrystalline Quartz (SiO2)