Mineral, Possibly Rock Fragment Containing A Mineral

Uncertain polished mineral specimen

Indeterminate; possibly quartz or feldspar with iron-oxide staining

Sandstone

Arenite

Sandstone River Cobble

Arenite (SiO2 based)

Fossil-bearing concretion, possibly containing a fossil shell or other organic inclusion

Calcareous concretion; exact fossil and host-rock composition are not identifiable from the image

Fossiliferous Shale (with Vertebrate Bones)

Laminated Mudstone containing Fossilized Bone (Apatite)

Weathered quartz-rich rock, possibly granite or quartzite

Indeterminate; likely quartz–feldspar aggregate, potentially granitic or quartzitic material

Likely quartz-rich gravel fragment (uncertain identification)

Quartz, silicon dioxide (SiO₂), possibly mixed with feldspar or other light-colored minerals

Granite Sand (Decomposed Granite)

Grus / Quartz-Feldspar Detritus

Granite

Felsic intrusive igneous rock

Likely mica-rich metamorphic rock (schist)

Mica schist, probably biotite–muscovite schist; exact identification requires closer examination

Quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂), possibly quartzite with minor iron-oxide inclusions

Polished brecciated jasper

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

Conglomerate

Conglomerate (clastic sedimentary rock)

Tumbled or weathered gneiss

Feldspar–quartz–mica gneiss (composition variable)

Raw quartz-bearing rock, possibly iron-stained quartz or pegmatitic quartz

Quartz (SiO₂), likely with iron-oxide staining and associated feldspar or mica

Iron-rich breccia or weathered ironstone

Goethite–hematite-bearing ferruginous rock, possibly limonite

Quartz vein in host rock (possibly milky quartz with iron-stained material)

Quartz, SiO₂, with an unidentified host rock and possible iron-oxide staining

Sandstone

Arenite (predominantly Quartz Sandstone)

Likely tumbled calcite or pale limestone fragment

Calcite (CaCO₃), possibly microcrystalline limestone

Red Sandstone

Arenite with iron oxide (Hematite) cement

Quartz-rich pegmatite, possibly rose quartz

Quartz (SiO₂) in a coarse granitic pegmatite matrix, with iron-oxide staining

Sandstone with Magnetite and Iron Staining

Clastic Sedimentary Rock (contains Fe3O4 and Limonite/Hematite)

Weathered granitic rock

Granite or granodiorite; chiefly quartz, feldspar, and mica/amphibole

Sandstone (River Stone)

Arenite (composed primarily of SiO2)

Sandstone (Weathered Pebble)

Arenite (SiO2 primarily)

Likely quartz-rich chalcedony or agate fragment

Microcrystalline quartz (SiO₂), possibly iron-oxide-stained chalcedony/agate

Weathered iron-rich rock, possibly oxidized basalt or laterite

Indeterminate; likely iron-oxide-bearing mafic rock (basaltic composition)

Granite or granitic gneiss

Quartz–feldspar–mica aggregate; likely weathered granite, possibly foliated gneiss

Brecciated jasper/chalcedony (iron-stained silica)

Microcrystalline quartz, SiO₂, with iron-oxide inclusions

Sandstone (Quartzose)

Arenite (primarily SiO2)

Sandstone

Arenite

Small quartz-rich stone, possibly iron-stained quartz or jasper

Quartz (SiO₂), potentially with iron-oxide inclusions

Sandstone (Pebble/Conglomerate fragment)

Sandstone (clastic sedimentary rock)

Likely limestone or chalk fragment

Calcite-rich carbonate rock; primarily calcium carbonate (CaCO₃)

Red Sandstone

Arenite (Fe2O3 rich)

Weathered quartz-rich pebble, possibly milky quartz

Quartz (SiO₂), provisionally identified

Greywacke (River Pebble with Quartz Veins)

Greywacke (Indurated Sandstone); Veins: SiO2 (Quartz)

Amygdaloidal Basalt

Amygdaloidal Basalt

Unidentified pale sedimentary rock, likely limestone

Calcite-rich limestone (CaCO₃), possibly fossiliferous or weathered micritic limestone

Unidentified small rock fragments

Indeterminate from image; possibly quartz-rich material

Shale (possibly)

Shale (fine-grained clastic sedimentary rock)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)