Organic (Geological Relative)

Moqui Marble (Shaman Stone)

Ironstone Concretion (Fe2O3) - primarily Hematite or Goethite shell with Sandstone core

Greenschist

Chlorite-actinolite schist

Amber

Succinite (Approximate formula: C10H16O)

Ferruginous Sandstone Concretion (Ironstone Phosphorite)

Ferruginous Sandstone (variable Fe-oxide/hydroxide composition)

Jasper

Silicon Dioxide (SiO2) with impurities

Chert (Jasper variation)

Silicon Dioxide (SiO2)

Orange Calcite (Polished Sphere)

Calcium Carbonate (CaCO3)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (Smooth River Pebble)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Glauconitic Sandstone

Glauconitic Quartz Arenite

Chert (specifically Flint or Jasper variant)

Microcrystalline quartz (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Chert

Cryptocrystalline Quartz (SiO2)

Limestone Pebble

Calcium Carbonate (CaCO3)

Propylitic Altered Andesite

Hydrothermally Altered Andesite

Fluorite

Calcium Fluoride (CaF2)

Limestone with Fossil Fragment

Sedimentary carbonate rock (CaCO3)

Limonite and Goethite encrusted Chert/Ironstone

Hydrated Iron Oxide (FeO(OH)·nH2O) with cryptocrystalline Silica (SiO2)

Chalcedony (variations like Agate or Jasper)

Chalcedony (SiO₂ - microcrystalline quartz)

Basalt

Basalt (Mafic volcanic rock)

Ammonite Fossil (Polished Half / Cleoniceras)

Ammonoidea (Subclass), often Cleoniceras genus; fossilized with Calcite (CaCO3) and Aragonite

Fossilized Plant or Tree Bark

Lepidodendron or Sigillaria (example genera)

Basalt

Mafic extrusive volcanic rock (composed primarily of Plagioclase feldspar and Pyroxene)

Basalt

Extrusive Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)

Likely basalt or other dark igneous rock

Basalt; predominantly plagioclase feldspar and pyroxene, possibly olivine

Green Aventurine

Aventurine (a variety of Quartz, SiO2)

Possible basalt pebble

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene

Petrified Wood

Silicified Wood (primarily Quartz / Chalcedony: SiO2)

Basalt Pebble

Basalt (Extrusive Mafic Igneous)

Fossiliferous Rock (Invertebrate Fossil in Matrix)

Fossiliferous limestone or shaly matrix containing skeletal fossil remains

Concretion

Septarian Concretion (Fragmentary)

Sandstone

Arenite

Chert (Jasper/Flint variant)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Chert (variations include Flint)

Silicon Dioxide (SiO2)

Black Jasper (Etched)

Silicon Dioxide (SiO2) with impurities

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert with Limestone matrix

Microcrystalline silica (SiO2) in Calcite (CaCO3) matrix

Moss Agate

Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)

Jasper

Microcrystalline Quartz (SiO2)

Jasper

Silicon Dioxide (Microcrystalline Quartz, SiO2)