Sedimentary Rock (Specifically A Clastic Sedimentary Rock Formed Into A Cobble)

River Pebble (Likely Chert or Fine-Grained Sandstone/Quartzite)

Siliciclastic clast (likely Chert or Quartzarenite/Quartzite pebble)

Banded Chert or Agate

Silicon Dioxide (SiO2)

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert / Jasper / Agate (Chalcedony Group)

Microcrystalline Quartz (SiO2)

Pink Granite

Granite (Felsic Plutonic Rock)

Quartzite

Quartzite (primarily SiO2)

Chert (varietal: Jasper or Flint)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Pumice (likely weathered/water-worn)

Vesicular volcanic glass

Travertine

Calcareous Tufa / Travertine (CaCO3)

Serpentine (Serpentinite)

Antigorite, Lizardite, or Chrysotile (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4

Sandstone (Ferruginous)

Arenite (SiO2 with Iron Oxide impurities)

Glauconite (Glauconitic Sandstone)

Glauconite [(K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2]

Concretion (Sandstone)

Sandstone Concretion

Quartzite

Quartzite (primarily SiO2)

Druzy Quartz on Limestone

Silicon Dioxide (SiO2)

Jasper or Chalcedony

Microcrystalline Quartz (SiO2)

Dalmatian Stone

Dalmatian Jasper (Aplitic Rock)

Chert (Nodule)

Silicon Dioxide (SiO2)

Bituminous Coal

Organic Sedimentary Rock (Carbon-based)

Chert with Asphaltum (or Tar)

Silica (SiO2) with natural Bitumen/Asphaltum

River Rock (Basalt)

Aphanitic Basaltic Rock

Quartzite

Quartzite (primarily SiO2)

Tumbled Carnelian and Quartz Mix

Silicon Dioxide (SiO2) with iron oxide impurities

Carnelian (Carnelian Agate)

Silicon dioxide (SiO2) - a variety of Chalcedony

Chert (Flint)

Cryptocrystalline Quartz (SiO2)

Quartz Geode (partially opened)

Silicon Dioxide (SiO2) with iron staining

Chert (Chert / Flint)

Silicon dioxide (SiO2) - Microcrystalline quartz

Sandstone Geode (Unbroken)

Siliciclastic sedimentary rock (primarily Quartz)

Halite (Rock Salt)

Halite (Sodium Chloride, NaCl)

Basalt (Stream-worn Cobble)

Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

Marble

Metamorphosed Limestone/Dolomite

Riverstone Quartzite

Quartzite (primarily SiO2)

Pyrite in Shale

Iron Sulfide (FeS2) in Argillaceous Shale

Quartzite

Quartzite (SiO2)

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Orange Calcite

Calcium Carbonate (CaCO3)

Red Jasper

Jasper (a variety of Chalcedony, SiO₂ with iron oxide inclusions)

Chert (and Chert Flake)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Ironstone (likely siderite or goethite-rich siltstone)

Ferruginous Siltstone

Garnet Schist or Garnet-bearing Quartzite

Metamorphic rock containing Almandine Garnet (Fe3Al2(SiO4)3) and Quartz (SiO2)

Basalt with Amygdaloidal Inclusions

Aphanitic Mafic Volcanic Rock (Basalt)