Rock (Likely Sedimentary)

Fossilized Gastropod in Chert/Limestone

Internal mold of Gastropoda (Class) with CaCO3 or SiO2 mineral formula

Pink Granite

Phaneritic Felsic Igneous Rock (Rich in K-Feldspar)

River Stone (likely Basalt or Chert)

Silicon Dioxide (SiO2) for chert or Mafic Extrusive Rock for basalt

Granite

Granite

Conglomerate

Conglomerate (Detrital Sedimentary Rock)

Quartz

Quartz (SiO2 - Silicon Dioxide)

Agate (specifically a Blue Agate Geode Slice)

Chalcedony (cryptocrystalline variety of Quartz); SiO2

Quartz (pebble)

Quartz (SiO₂)

Quartzite (River Pebble)

Metamorphosed Quartz Sandstone (SiO2)

Porphyritic Basalt (or Andesite) Pebble

Porphyritic Mafic Volcanic Rock

Blue Chalcedony (likely dyed)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chert (Flint Pebbles)

Microcrystalline quartz (SiO2)

Ocean Jasper

Spherulitic Chalcedony (SiO2)

Chert (Tan/Yellow variety)

Microcrystalline Quartz (SiO2)

Porphyritic Basalt

Amygdaloidal Porphyritic Basalt

Painted Garden Rock (likely Granite or Limestone base)

Silicon Dioxide (SiO2) / Calcium Carbonate (CaCO3) based substrate with Acrylic/Enamel pigments

Fossilized Megalodon Tooth Fragment

Otodus megalodon (Carcharocles megalodon fossil)

Jasper (likely Lake Superior Jasper)

Silicon Dioxide (SiO2) with iron oxide inclusions

Chert (Yellow Jasper variant)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Shale

Shale (Consolidated fine-grained clay/silt)

Granite with Orthoclase and Hematite Staining

Phaneritic Felsic Igneous Rock (primarily SiO2 with KAlSi3O8)

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Sandstone (with potentially high Feldspar/Arkose content)

Clastic sedimentary rock (SiO2 dominated)

Petrified Wood

Silicified Wood (SiO2)

Quartzite (Beach Pebble)

Quartzite (Composition: SiO2)

Quartz Pebble (with Iron Inclusions)

Silicon Dioxide (SiO2)

Amber-bearing Coal/Sedimentary Rock

Bituminous coal or carbonaceous siltstone with Fossilized Tree Resin (C10H16O)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Veined Limestone (Micrite) with Quartz/Calcite Veins

Calcium Carbonate (CaCO3) with Silicate or Carbonate inclusions

Sandstone

Arenite

Jasper

Silicon Dioxide (SiO2) with impurities (mostly Iron Oxides)

Iron Ore / Ironstone Concretion

Mixture of iron oxide/hydroxide minerals, likely some combination of Hematite (Fe2O3), Goethite (α-FeOOH), and Limonite (a general term for hydrated iron oxides of variable composition) or potentially Bauxite (a mixture of aluminum hydroxides, often with iron oxides, (Al(OH)3) and FeO(OH)). The visual characteristics strongly suggest iron-rich material.

Petrified Wood

Silicified Wood (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline silicon dioxide (SiO2)

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Sandstone

Arenite (primarily SiO2)

Coquina or Fossiliferous Limestone

Fossiliferous Calcarenite (CaCO3)

Jasper with Chert

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Sandstone

Clastic sedimentary rock (primarily SiO2)

Granite Pebble (Salt and Pepper Granite)

Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Biotite/Amphibole)

Bicolor Quartz (Milk Quartz with Slag or Dark Inclusions)

Silicon Dioxide (SiO2) with impurities

Petrified Wood

Silicified Wood (SiO2)