Mineral (Sedimentary Context)

Quartz (possibly milky quartz)

Quartz (Silica; SiO₂)

Onyx Marble (also commonly called Onyx)

Calcite (CaCO3), often with other mineral impurities

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Sedimentary/Metamorphic Matrix

Sandstone with trace fossil

Sandstone, possibly with Skolithos or similar trace fossil

Tiger's Eye (often misinterpreted as Gold Ore in this context)

Pseudomorph of Quartz after Crocidolite (SiO2)

Quartz (Druzy) in host rock

SiO₂ (Silicon Dioxide) as Quartz, with unspecified host rock components (likely silicates and iron oxides)

Quartz

Quartz (SiO2 - Silicon Dioxide)

Gneiss

Gneiss (pronounced 'nice')

Petrified Wood

Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)

Potassium-Rich Silicate Clay (inferred from biological context)

Phyllosilicate group (likely Illite or Smectite within surrounding soil substrate)

Rutilated Quartz

Quartz (SiO2) with Rutile (TiO2) inclusions

Pebble (likely a type of sandstone or quartzite pebble)

Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.

Rounded pink granite pebble

Granite, a coarse-grained felsic intrusive igneous rock composed primarily of quartz, feldspar, and minor mica or amphibole

Quartz pebble

Silicon dioxide (SiO2)

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.

Banded sandstone

Quartz-rich sandstone (quartz arenite or feldspathic sandstone; exact type cannot be determined from the image)

Magnetite (Iron Ore)

Iron(II,III) oxide (Fe3O4)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Granite (likely a river or beach pebble)

Granite (a felsic intrusive igneous rock primarily composed of quartz, feldspar, and mica)

Pyrite

Iron Sulfide (FeS2)

Shale fragment

Shale (clay mineral rich sedimentary rock)

Banded gneiss

Foliated gneiss, likely quartz–feldspar–biotite or amphibole gneiss

Sandstone

Clastic sedimentary rock (Quartz arenite or Arkose)

Tumbled jasper (likely picture/brecciated jasper)

Microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides

Banded Sedimentary Rock

Sedimentary rock with mineral veins/banding

Green Calcite

Calcium Carbonate (CaCO3)

Sedimentary Rock Fragments

Clastic Sedimentary Rock

Quartz

Silicon dioxide (SiO2)

Blue Apatite

Ca5(PO4)3(F,Cl,OH)

Pyrite

Iron Sulfide (FeS2)

Pyrite

Iron sulfide (FeS2)

Hematite

Iron(III) oxide (Fe2O3)

Veined Sandstone with Calcite Veins

Sedimentary sandstone with hydrothermal/mineral veins

Limonite Geode (Ironstone Concretion)

Limonite [FeO(OH)·nH2O] with possible Quartz or Calcite interior

Calcite

Calcite (Calcium Carbonate, CaCO3)

Magnetite / Ironstone

Magnetite (Fe3O4)

Pyrite

Iron Disulfide (FeS2)

Pyrite

Iron Disulfide (FeS2)

Banded gneiss

Foliated gneiss, likely quartz–feldspar–mica gneiss

Banded gneiss

Quartz–feldspar gneiss, possibly biotite-bearing; exact identification requires testing

Banded gneiss

Gneiss, commonly quartz–feldspar–mica gneiss

Blue Apatite

Ca5(PO4)3(F,Cl,OH)