Sedimentary Rock (Specifically A Concretion Or Possibly A Geode)

Chalcedony or Chert/Jasper with secondary mineral staining

SiO2 (for chalcedony/quartz) with possible secondary copper minerals (e.g., CuSiO3·nH2O for chrysocolla, Cu2(CO3)(OH)2 for malachite) or iron oxides/hydroxides.

Geode (Unopened)

Siliceous Geode (SiO2)

Druzy Quartz

Silicon Dioxide (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Shale (possibly)

Shale (fine-grained clastic sedimentary rock)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Milky Quartz Geode or Druzy Quartz

Silicon Dioxide (SiO2)

Chert (specifically a Worked Flint/Knapped Flake)

Chert / Flint (Microcrystalline Quartz, SiO2)

Conglomerate

Conglomerate (clastic sedimentary rock)

Druzy Quartz (part of a Geode)

Silicon Dioxide (SiO2)

Sandstone (Graywacke)

Clastic Sedimentary Rock (Lithic Sandstone)

Sandstone

Clastic Sedimentary Rock (composed mostly of quartz, SiO2)

Pebble or Cobble (likely composed of sandstone or conglomerate)

Clastic Sedimentary Rock (specific name like sandstone, conglomerate, or breccia would require microscopic analysis of clast size and angularity)

Limestone (specifically Travertine or Tufa)

Calcium Carbonate (CaCO3)

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.

Ironstone Concretion (Moqui Marble variety)

Ferruginous Sandstone Concretion

Sandstone (with Concretion)

Arenite / Quartzose Sandstone

Red Jasper (possibly banded)

Silicon Dioxide (SiO2) with iron oxide inclusions

Green Druzy Quartz (Prasiolite)

Silicon Dioxide (SiO2) with inclusions (typically Chlorite or Actinolite)

Basalt

Basalt (composition of plagioclase feldspar and pyroxene)

Quartz Geode

Silicon Dioxide (SiO2) within a geode

Quartz / Common Agate

Silicon Dioxide (SiO2)

Conglomerate

Conglomerate (clastic sedimentary rock)

Limestone (specifically Grainstone or Micrite)

Calcium Carbonate (CaCO3)

Quartz (likely Milky Quartz)

Quartz (SiO₂ - Silicon Dioxide)

Fossil Coral

Coral Limestone (a type of biogenic sedimentary rock)

Quartz (possibly milky quartz)

Quartz (Silica; SiO₂)

Ironstone Concretion

Siderite or Limonite Concretion

Quartz

Quartz (SiO2 - Silicon Dioxide)

Sandstone Geode (Ironstone Concretion)

Arenite with Limonite/Hematite matrix (SiO2 with Fe-oxides)

Unable to identify - Image contains non-geological items

Thunderegg (specifically a Jasper/Agate-filled Geode nodule)

Silicon Dioxide (SiO2) within Rhyolitic Matrix

Quartz Geode

Silicon Dioxide (SiO2)

Calcite (or Alabaster, if truly carved)

Calcium Carbonate (CaCO3)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Sandstone Concretion

Clastic Sedimentary Concretion (primarily SiO2 with Fe2O3 cement)

Druzy Quartz on Sandstone

Silicon Dioxide (SiO2) with Quartz crystals

Moqui Marble (Moqui Ball)

Ironstone Concretion (Goethite/Hematite cemented Sandstone)

Quartz Geode

Silicon Dioxide (SiO2)

Quartz Geode

Silicon Dioxide (SiO2) in Host Rock

Ironstone Concretion

Limonitic/Hematitic Concretion

Chalcedony Geode

Chalcedony (SiO2) within a geode structure