Rock (Likely Sedimentary)

Polished yellow jasper or opaque chalcedony bead

Microcrystalline quartz (SiO₂), likely iron-oxide-stained jasper

Basalt with Jasper Veining

Basaltic Rock with Cryptocrystalline Quartz (SiO2)

Likely weathered fossil bone fragment

Indeterminate fossilized bone; taxonomic identification requires microscopy and locality data

Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)

Quartz (SiO₂)

Chert (Jasper variety) with Iron Oxide staining

Cryptocrystalline Quartz (SiO2) with Goethite/Limonite impurities

Weathered sandstone or iron-stained sedimentary rock

Likely quartz-rich sandstone; exact identification is uncertain from the photograph

Pyrite-bearing rock (likely pyrite in a quartz or sulfide-rich matrix)

Pyrite, FeS₂; the gray host may be quartz, carbonate, or another sulfide-bearing rock

Milky Quartz in Conglomerate Matrix

Silicon Dioxide (SiO2) within Clastic Sedimentary Rock

Quartz-rich gravel fragment

Quartz (silicon dioxide, SiO₂), possibly with feldspar or carbonate inclusions

Sandstone (likely River-tumbled Picture Sandstone)

Arenite (predominantly SiO2 with iron oxide impurities)

Sandstone (Muddy/Silty Variety)

Arenite with high silt/clay content (clastic sedimentary rock)

Weathered limestone or calcitic cave deposit

Calcite (CaCO₃), likely porous limestone/travertine

Jasper with Quartz inclusions

Silicon Dioxide (SiO2) - Microcrystalline Chalcedony

Sandstone (likely Quartzose Sandstone)

Arenite (primarily SiO2)

Rounded gray-brown cobble, likely weathered sandstone or quartzite

Tentatively quartz-rich sandstone (SiO₂-dominated); exact identification requires hardness and acid tests

Banded Metamorphic Rock (likely Quartzite or Serpentinite/Soapstone)

Metamorphic Rock (possibly a banded Quartzite or a foliated Serpentinite/Talc Schist based on appearance, general term for such a rock is 'Banded Metamorphic Rock' or 'Gneiss' if pronounced banding of different minerals)

Layered shale and sandstone gorge

Shale and thin-bedded sandstone, likely Devonian or older sedimentary strata

Rounded weathered rock, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; precise identification requires testing

Greywacke (River Pebble)

Greywacke sandstone with quartz veining

Chert Pebble (with Quartz Vein)

Chert (Cryptocrystalline Silica - SiO2)

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Note regarding baguette production (not a rock)

Digital text image - Somali language

Weathered sandstone or siltstone boulder

Indeterminate clastic sedimentary rock, likely quartz-rich sandstone (SiO₂-dominant)

Weathered iron-rich rock (probable laterite or limonite-bearing stone)

Goethite–limonite mixture, commonly written FeO(OH)·nH₂O, with possible quartz and clay minerals

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Xenolith in Basalt

Mafic Igneous Rock with Felsic Inclusion

Basalt with Iron Oxidation (Lattice/Veined)

Mafic Volcanic Rock (principally Plagioclase and Pyroxene)

Fossiliferous Rock (likely Dinosaur Fossil in Matrix)

Permineralized Vertebrate Fossil (Calcium Carbonate/Silica replaced bone material)

Tumbled brown chalcedony (likely jasper or agate)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide staining

Petrified Wood

Silicified Wood (SiO2)

Granite

Granite (composed of Quartz, Feldspar, and Mica)

Mica schist, likely biotite–muscovite schist

Mica schist; predominantly quartz, feldspar, biotite and/or muscovite mica. Exact mineral composition cannot be confirmed from the photograph alone.

Undetermined Due to Blur (Possible Flesh-Tone Mineral)

Unknown (Insufficient Visual Clarity)

Garnetiferous Pegmatite

Pegmatite with Almandine Garnet and Muscovite

Tumbled reddish sandstone pebble

Quartz-rich sandstone, likely ferruginous arkose or quartz arenite

Beaded Jewelry (Assorted Gemstones)

Various minerals, including but not limited to Quartz (SiO2), Garnet (X3Y2(SiO4)3), Jade (Na(Al,Fe)Si2O6), Amethyst (SiO2),等の多様な組み合わせ

Banded gneiss pebble

Gneiss, likely quartz–feldspar–mica gneiss

Green Chalcedony (likely Green Agate or Chrysoprase)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Porphyritic Basalt (River Rock)

Porphyritic Basalt

River Stone (likely Mudstone or Siltstone)

Lutite (Clastic sedimentary rock composed of clay and silt-sized particles)

Weathered mafic rock (probable basalt or gabbro fragment)

Basalt–gabbroic rock; chiefly plagioclase feldspar and pyroxene, possibly olivine

Biotite Schist (likely)

Biotite Schist (rock), Biotite (mineral)