Mineral, Often A Rock Given Its Aggregate Nature

Laterite

Laterite (no specific mineral formula as it's a rock type)

Milky Quartz

Silicon Dioxide (SiO2)

River Rocks (Black)

Various lithologies (e.g., basalt, chert, obsidian for black varieties), mechanically rounded clasts

Granite Pebble (River Rock)

Granite (composed primarily of Quartz, Feldspar, and Mica)

Yellow Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Conglomerate

Conglomerate (clastic sedimentary rock)

Sandstone

Clastic Sedimentary Rock (composed mostly of quartz, SiO2)

Basalt

Basalt (primarily composed of Plagioclase feldspar and Pyroxene)

Chert / Flint

Chert (varieties include Flint)

River Stone (likely Siltstone or fine-grained Basalt)

Clastic Sedimentary (Siltstone) or Mafic Igneous (Basalt)

Basalt

Basalt (Mafic volcanic rock)

Sandstone (Quartz Arenite)

Sandstone (Chemical formula: primarily SiO2)

Chert Nodule (Flint)

Chert (Cryptocrystalline Silica - SiO2)

Conglomerate

Conglomerate (Detrital Sedimentary Rock)

Granular Sandstone

Arenite (variable composition, primarily SiO2)

Quartz in Matrix (possibly Basalt or Siltstone host)

Silicon Dioxide (SiO2) in Host Rock

Gold-bearing Quartz with Iron Oxides

Quartz (SiO2) with Limonite/Goethite (FeO(OH)) and Pyrite (FeS2)

Chert (White/Gray variety)

Chert (SiO2)

Sandstone with Quartz Veining

Clastic sedimentary rock (SiO2 dominated)

Basalt

Basalt (composition of plagioclase feldspar and pyroxene)

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Basalt

Extrusive mafic igneous rock

Basalt

Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Basalt with Quartz Veining

Basalt (Mafic Extrusive Igneous Rock) with SiO2 (Silicon Dioxide) veins

Desert Varnish on Sandstone

Ferromanganese coating on Quartz Arenite

Quartzite River Rock

Quartzite (SiO2)

Carnelian

Carnelian (a variety of Chalcedony, SiO2)

Jasper with Hematite Inclusions

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3)

Chert (Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Red Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Smoky Quartz (Tumbled)

Silicon Dioxide (SiO2)

Basalt with Phenocrysts (Porphyritic Basalt)

Porphyritic Basalt (primarily Plagioclase and Pyroxene)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Basalt

Basalt (dominated by plagioclase feldspar and pyroxene)

Talc

Talc (Mg₃Si₄O₁₀(OH)₂)

Weathered Volcanic Rock (possibly Rhyolite or Andesite Pebble)

Volcanic rock (e.g., Rhyolite or Andesite, specific identification would require thin section analysis or chemical assay). Mineral composition: Primarily feldspars (orthoclase and/or plagioclase), quartz (in rhyolite), micas, amphiboles, and sometimes pyroxenes.

Basalt with Calcite Veins

Aphanitic mafic volcanic rock with CaCO3 inclusions

Basalt with Scoria/Vesicular texture

Vesicular Basalt (primarily Plagioclase feldspar, Pyroxene, and Olivine)

Quartz Pebble

Silicon Dioxide (SiO2)

Limonite (Iron Stone)

Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O

Basalt (Vesicular/Scoriaceous)

Extrusive Mafic Volcanic Rock (Primarily Plagioclase Feldspar and Pyroxene)

Agate

Silicon Dioxide (SiO2)