Mineral, Specifically A Rock Fragment

Sandstone Pebble

Sandstone (Silicon dioxide-rich clastic sedimentary rock)

Jasper (specifically Yellow or Bumblebee-like Jasper)

Silicon Dioxide (SiO2) with impurities

Basalt River Stone

Basalt (Mafic volcanic rock, primarily Plagioclase and Pyroxene)

Desert Rose

Gypsum (variety Selenite) - CaSO4·2H2O

Sandstone

Clastic Sedimentary Rock

Sandstone

Sedimentary Clastic Rock

Calcite

Calcite (CaCO₃), likely crystalline limestone or marble fragment

Sandstone

Clastic Sedimentary Rock

Milky Quartz

Silicon Dioxide (SiO2)

Granite Gneiss

Gneiss (High-grade Metamorphic Rock)

Sandstone Pebble

Sedimentary quartz arenite

Quartz-rich breccia or vein quartz fragment

Quartz (SiO₂), likely with iron-oxide staining and attached host rock

Sandstone

Arenite (SiO2 with various cementing minerals)

White tumbled stone, likely quartz or calcite

Indeterminate; possibly quartz (SiO₂) or calcite (CaCO₃)

Red Sandstone

Sandstone (principally Quartz with Iron Oxide coating)

Sandstone with Manganese Staining

Quartz Arenite / Sedimentary Rock

Pink Granite

Phaneritic Felsic Igneous Rock (Rich in K-Feldspar)

Brown Sandstone (River Rock)

Arenite

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Pink Granite

Phaneritic Igneous Rock (high K-Feldspar content)

Likely iron-rich slag or weathered ironstone

Hematite–goethite-rich material (Fe₂O₃/FeO(OH)); possibly industrial iron slag

Amphibolite (specifically Hornblende Schist/Gneiss)

Amphibole-rich Metamorphic Rock

Sandstone (with Iron Staining)

Clastic sedimentary rock (SiO2 with Fe2O3 oxides)

Shale

Argillite / Shale

Sandstone (Tumbled / Rounded)

Sedimentary Rock (Quartz arenite)

Pale green tumbled mineral fragment, likely serpentine or green calcite

Probable serpentine-group mineral (Mg3Si2O5(OH)4) or, less likely, calcite (CaCO3); identification is uncertain from the photograph

Porphyritic Igneous Rock / Basalt or Andesite Xenolith in Granite or Quartzite

Silicate rock with contrasting xenolith/inclusion

Green Quartzite (Aventurine-like)

Quartzite (primarily SiO2 with chromium-rich mica or chlorite inclusions)

Pink Granite

Phaneritic Felsic Igneous Rock (Granite)

Quartz fragment

Silicon dioxide (SiO2)

Polished pink chalcedony (likely pink agate/geode)

Microcrystalline quartz, SiO₂; chalcedony with iron-bearing inclusions and possible druzy quartz

Conglomerate / Breccia Matrix (Aggregated Rock)

Sedimentary Breccia / Conglomerate

Granite Pegmatite

Phaneritic Plutonic Igneous Rock

Chipped Glass/Plastic Fragment

Silicon dioxide (SiO2) for glass (amorphous) or various polymer compounds for plastic

Dark mafic rock, likely basalt

Basalt (fine-grained assemblage chiefly plagioclase and pyroxene, commonly with olivine and iron oxides)

Pink chalcedony (likely rough agate/chalcedony)

Microcrystalline quartz, SiO₂; chalcedony variety, possibly iron-bearing

Quartz (likely Clear Quartz or Rock Crystal)

Quartz (SiO2)

Weathered limestone with possible fossil or calcite coating

Limestone; primarily calcium carbonate (CaCO₃), chiefly calcite

Tumbled or naturally etched mica-rich mineral specimen, likely muscovite

Muscovite, KAl₂(AlSi₃O₁₀)(OH)₂; possibly phlogopite mica

Sandstone

Sedimentary Rock (Quartz Sandstone)

Pink Granite

Granite (Phaneritic Acidic Igneous Rock)

Sandstone

Arenite (SiO2 based typically)