Not A Rock Or Mineral (Anthropogenic Material)

Sandstone

Sedimentary Rock (Quartz Sandstone)

Pink-and-white quartz-rich pebble

Quartz (SiO₂), likely massive quartz with iron-oxide staining and possible feldspar inclusions

Quartz Vein in Hematitic Siltstone

Hydrothermal Quartz (SiO2) in Ferriferous Matrix

Sandstone

Sedimentary Rock (Quartz arenite)

Sandstone

Clastic Sedimentary Rock

Pale blue-gray quartz-rich pebble (tentative)

Quartz, SiO₂, possibly chalcedony or a weathered metamorphic fragment

Tumbled brown mineral/rock specimen

Indeterminate from image; likely brown jasper, chert, or iron-stained quartzite

Serpentinite (serpentinized ultramafic rock), possibly with chromite

Serpentine-group minerals, chiefly lizardite and chrysotile; commonly derived from peridotite or pyroxenite, with possible chromite and magnetite

Asphalt aggregate pavement

Bituminous asphalt concrete containing crushed stone aggregate

Unidentified gray stone/concrete-like fragment

Indeterminate; likely a fine-grained carbonate or cementitious geological fragment

Sandstone

Sedimentary Rock (Quartz Arenite)

Sandstone (Ferruginous)

Arenite (with Iron Oxide cement)

Rounded gray river pebble, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; commonly basalt (plagioclase ± pyroxene/olivine)

Granite / Diorite (Granitoid)

Granitoid rock (composed mainly of Quartz, Feldspar, and Amphibole/Biotite)

Basalt Breccia

Volcanic Breccia (composed of basaltic clasts in a fine-grained matrix)

Sandstone (Quartz-rich)

Arenite

Sandstone

Clastic Sedimentary Rock

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Iron-stained milky quartz vein

Quartz (SiO₂), with iron-oxide/hydroxide staining and minor dark inclusions

Botryoidal chalcedony (possibly agate/geode material)

Microcrystalline quartz, SiO₂; commonly chalcedony with quartz-lined cavities and iron-oxide staining

Weathered granite or granitic gneiss fragment

Granite, predominantly quartz, feldspar, and dark mica/amphibole

Fire Opal (in Matrix)

Hydrated Silica (SiO2·nH2O)

Breccia

Breccia (Sedimentary Clastic Rock)

Fossilized Tooth

Vertebrate Fossilized Tooth (Mineralized Biogenic Material)

Sandstone (with iron staining)

Quartz Arenite / Ferruginous Sandstone

Small pale stone fragment (undetermined)

Unidentified; the image lacks diagnostic detail for a reliable identification

Sandstone

Arenite (clastic sedimentary rock)

Sandstone

Arenite (Sedimentary rock comprising sand-sized grains)

Green sea glass (likely)

Man-made glass, likely soda-lime silicate glass; not a natural mineral or rock

Red Sandstone

Arenite (primarily SiO2 with Fe2O3)

Sandstone / Chert Gravel

SiO2 (Silicon Dioxide based clastic sedimentary rock)

Sandstone (Micaceous)

Clastic Sedimentary Rock - Micaceous Litharenite (SiO2 principal)

Tumbled dark-green stone, possibly jade or serpentine

Undetermined; candidates include jadeite (NaAlSi₂O₆), nephrite (Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂), or serpentine-group minerals

Polished banded gneiss

Biotite–quartz–feldspar gneiss, locally migmatitic

Sandstone

Arenite (composed primarily of SiO2)

Sandstone

Arenite (specifically Quartz Arenite)

Quartz

Silicon Dioxide (SiO2)

Unidentified fine mineral/rock powder

Indeterminate from image; possibly crushed quartz-rich sand or finely milled rock

Quartz Crystal Fragment

Silicon Dioxide (SiO2)

Weathered granite or granitic gneiss block

Granite, chiefly quartz, feldspar, and mica; possibly gneiss if the visible banding is structural

Quartz Pebble

Silicon Dioxide (SiO2)

Granite (likely weathered feldspathic granite)

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