Sedimentary Rock (Altered)

Sandstone

Arenite (SiO2 predominantly)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 oxides)

Conglomerate

Conglomerate (a clastic sedimentary rock)

Sandstone

Clastic sedimentary rock (primarily SiO2)

River Rocks (Basalt and Sedimentary Stones)

Mafic Igneous Rock (Basalt) and Clastic Sedimentary Rock

Sedimentary rock with quartz veining

Laminated siltstone or mudstone with hydrothermal quartz veins

Sandstone

Arenite (primarily SiO2)

Fossil Bivalve Shell

Class Bivalvia (e.g., Veneriidae family)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Iron Oxide cement)

Shale

Fissile Mudstone

Sandstone (Ferruginous)

Clastic Sedimentary Rock (SiO2 with Fe2O3/FeOOH cement)

Fossiliferous Sandstone (with Brachiopod or Bivalve mold)

Clastic Sedimentary Rock with Macrofossil Mold

Sandstone (specifically Banded Sandstone)

Clastic sedimentary rock (primarily SiO2)

Metaconglomerate

Protolith: Conglomerate (comprising SiO2, Al2O3, etc.)

Sandstone (Banded Sandstone)

Clastic Sedimentary Rock (primarily SiO2 with iron oxide impurities)

Sandstone (Ferruginous)

Arenite (SiO2 with iron oxide impurities)

Quartz Geode

Silicon Dioxide (SiO2) within a geode

Sandstone (with Iron Staining)

Clastic Sedimentary Rock (primarily Quartz, SiO2)

Sandstone

Arenite

Druzy Quartz on Chert/Siltstone

Silicon Dioxide (SiO2) on Microcrystalline Silica/Siltstone matrix

Shale with Siltstone layering

Sedimentary Clastic Rock (Mudstone/Shale)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Green Opal

Hydrated Silica (SiO2·nH2O)

River Pebble (Gravel)

Clastic sedimentary rock (likely Siltstone or Mudstone pebble; SiO2 with various impurities)

Sandstone

Arenite (SiO2, often with CaCO3 or Fe2O3 cement)

Diorite (Dalmatian Stone)

Phaneritic Plutonic Diorite

Shale

Fissile mudstone (rich in clay minerals and quartz)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with iron oxide cement)

Sandstone

Arenite (composed primarily of SiO2)

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.

Sandstone (Greywacke)

Sandstone (SiO2 enriched with lithic fragments)

Gastropod Fossil (Snail Steinkern)

Class Gastropoda fossil, composed of Calcium Carbonate (CaCO3)

Chert / Flint

Cryptocrystalline quartz (SiO2)

Brown Sandstone

Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)

Chert / Chalcedony (likely carnelian or flint variety)

Silicon Dioxide (SiO2)

Sandstone

Arenite (primarily SiO2)

Sandstone with Quartz Veins

Arenite (primarily SiO2 with Fe2O3 staining)

Sandstone (Quartz-rich)

Arenite (primarily SiO2)

Chert

Chert (variant of microcrystalline quartz)

Agate Geode

Silicon Dioxide (SiO2)

Chert (potentially Flint or Mudstone)

Microcrystalline Quartz (SiO2)

Chert

Silicon dioxide (SiO2)