Rock (Likely Sedimentary)

Quartz (Milk/Citrine variety)

Silicon Dioxide (SiO2)

Sandstone (with secondary weathering/concretion)

Arenite (composed primarily of Quartz, SiO2)

Jasper (Ferruginous Quartz)

Silicon Dioxide (SiO2) with iron oxide inclusions

Fossiliferous limestone (likely crinoidal or shell limestone)

Calcite-rich limestone; predominantly CaCO₃, with visible fossil fragments

Shale

Fissile Mudstone

Sandstone (Ferruginous)

Clastic Sedimentary Rock (SiO2 with Fe2O3/FeOOH cement)

Sandstone Anvil / Nutting Stone

Quartzose Sandstone (Sedimentary Rock)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Rounded greenish river pebble, likely basalt or altered volcanic rock

Probable basalt (fine-grained mafic silicate rock), possibly epidote/chlorite-altered

Sandstone Pebble

Quartz Sandstone

Copper-bearing Quartz (likely Chrysocolla or Malachite staining)

Cuprite, Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O) or Malachite staining on Quartz/Host Rock

Sandstone

Arenite (primarily composed of SiO2)

Concretion

Sedimentary Concretion

Shale

Shale (Lutite)

Quartz Geode

Silicon Dioxide (SiO2) within a geode

Quartz (Milky Variant)

Quartz (Silicon Dioxide, SiO2)

Petrified Wood

Silicified Wood (SiO2)

Weathered sandstone or quartz-rich sedimentary pebble

Indeterminate lithic fragment; likely quartz arenite (sandstone)

Weathered quartz-bearing rock, possibly granite or gneiss

Indeterminate; likely quartz–feldspar–mica aggregate, possibly granitic gneiss

Agate

Silicon Dioxide (SiO2) - variety Chalcedony

Agate (specifically a Yellow/Honey Agate)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Quartz Crystal on Matrix

Silicon Dioxide (SiO2)

Banded Iron Formation (BIF)

Banded Iron Formation (Oxide Facies)

Fossilized Brachiopod Shell

Phylum Brachiopoda (likely Order Spiriferida or Strophomenida)

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Chert (Jasper variety)

Cryptocrystalline Quartz (SiO2)

Chert (River Pebble)

Microcrystalline silica (SiO2)

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Calcite

Calcite (calcium carbonate, CaCO₃)

Porphyritic polymictic breccia (likely volcanic breccia)

Volcanic breccia; probable polymictic andesite–dacite breccia with quartz/feldspar clasts

Iron-rich vesicular rock, possibly slag or weathered basalt

Identification uncertain; likely ferruginous basalt/ironstone, with possible anthropogenic iron slag

Limonite (Ochreous Sandstone)

Hydrous ferric oxides (FeO(OH)qnH2O)

Quartz geode (likely amethyst-bearing)

Silica geode; quartz, SiO₂, with possible amethyst and minor iron oxides

Concretionary limestone or calcarenite pebble

Micritic limestone/calcarenite, primarily calcite (CaCO₃)

Likely weathered sandstone or quartzite

Quartz-rich sandstone; possibly metamorphosed to quartzite (SiO₂-dominant)

Weathered banded sandstone pebble

Quartz-rich sandstone (predominantly SiO₂)

Fossiliferous limestone

Calcite-rich limestone (CaCO₃), containing possible fossil or peloidal inclusions

Chert (with Limonite staining)

Microcrystalline Quartz (SiO2)

Fossiliferous Limestone

Fossiliferous Calcilutite / Biomicrite

Coquina

Biogenic Limestone (Calcite, CaCO3)

Chert (often called Flint or River Stone)

Microcrystalline Quartz (SiO2)

Chert (Yellow or Tan Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)