Mineral, Possibly Rock Fragment Containing A Mineral

Unidentified gravel and stone fragments

Mixed, indeterminate lithologies; likely quartz, feldspar, and weathered silicate rock fragments

Quartz-rich rock fragment, possibly granite or quartzite

Indeterminate quartz-bearing silicate rock; likely quartz (SiO₂) with feldspar and/or mica

Sandstone (Calcareous/Lithic)

Sedimentary Rock (Clastic Sandstone with Calcium Carbonate cement)

Dark, weathered rock fragment (possibly basalt or iron-rich stone)

Indeterminate; possible basalt (plagioclase–pyroxene rock)

Likely weathered quartz-rich stone

Indeterminate; possibly quartz-bearing granite or milky quartz

Probable fossil tooth fragment

Indeterminate fossilized vertebrate tooth; species cannot be identified from this image

Pale blue-gray quartz-rich pebble (tentative)

Quartz, SiO₂, possibly chalcedony or a weathered metamorphic fragment

Quartz-rich rock fragment

Microcrystalline quartz (SiO₂), possibly chalcedony or quartz-bearing breccia

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)

Likely weathered iron-rich rock fragment

Indeterminate; possibly limonite/goethite-bearing sandstone or ironstone

Basalt with Xenolith

Extrusive Igneous Rock containing Mantle Xenolith

Uncertain small metallic-looking mineral/rock fragment

Indeterminate; possibly galena-bearing rock or metallic slag

Weathered granitic rock fragment

Granite, predominantly quartz–feldspar–mica assemblage

Sandstone (Greywacke/Siltstone variant)

Arenite / Wacke (SiO2 with diverse mineral inclusions)

Weathered greenish-gray rock fragment

Tentatively basaltic or mafic metamorphic rock; exact identification is uncertain from the photograph

Sandstone (with potential Concretion or Fossil fragment)

Arenite (primarily SiO2)

Shale

Laminated Mudstone

Asphalt Chunk

Asphalt concrete

Likely weathered granite or granitic pegmatite

Granite; chiefly quartz (SiO₂), feldspar, and mica

Greywacke (likely)

Greywacke (a type of sandstone)

Possible weathered quartz-rich rock or iron-stained mineral fragment

Indeterminate; possibly quartz (SiO₂) with iron-oxide inclusions

Tumbled quartz-rich rock, possibly calcite or sandstone

Indeterminate from photograph; likely microcrystalline quartz (SiO₂) or calcite (CaCO₃)

Iron-stained brown mineral/rock fragment

Most likely limonite/goethite-rich material (hydrated iron oxides), possibly weathered ironstone; exact identification requires testing

Sandstone

Arenite (SiO2 primarily)

Small weathered mineral/rock fragment

Indeterminate; possibly quartz-bearing feldspathic rock or calcite-rich specimen

Breccia

Breccia (Clastic Sedimentary Rock)

Sandstone

Arenite (SiO2 principal component)

Sandstone

Clastic Sedimentary Rock (composed mostly of quartz, SiO2)

Indeterminate metallic mineral fragments

Possibly pyrite, chalcopyrite, or metallic sulfide-bearing rock

Aggregate Concrete

Anthropogenic Conglomerate (Technosol)

Likely quartz-bearing rock fragment

Quartz (SiO₂), possibly in a weathered granitoid or metamorphic matrix

Dark brown mineral fragments, possibly garnet or iron-rich rock

Indeterminate from image; possible almandine garnet (Fe₃Al₂Si₃O₁₂) or limonite-rich material

Possible weathered metallic mineral specimen

Uncertain; possibly native copper-bearing rock or iron sulfide in a gray host matrix

Likely quartz-rich mineral fragment

Quartz (SiO₂), possibly iron-stained or included quartz

Greenstone (likely altered basalt or serpentinite)

Chlorite–epidote amphibolite/greenschist or serpentinite; exact identification requires testing

Polished fossil-bearing limestone pebble

Bioclastic limestone, chiefly calcite (CaCO₃), possibly containing a small shell or coral fragment

Probable iron-rich mineral or weathered rock fragment

Indeterminate; possibly limonite/goethite-bearing material

Sandstone

Arenite (composed primarily of SiO2)

Iron-rich brown stone, possibly weathered chert or ironstone

Undetermined; likely iron-oxide-bearing silica-rich rock (chert/ironstone)

Granite (likely weathered)

Granite, a quartz–feldspar–mica intrusive igneous rock

Sandstone (Graywacke)

Clastic Sedimentary Rock (Lithic Sandstone)

Coquina / Shelly Sandstone

Calcareous Sandstone / Coquina