Sedimentary (Alluvial Deposit)

Chert

Chert (SiO2)

Chert (Quartz Variety)

Chert (SiO2)

Tree Agate

Silicon Dioxide (SiO2) with Chlorite inclusions

Fossilized Bone Fragment

Permineralized Vertebrate Bone (Hydrox yapatite replaced by Silica or Calcite)

Ironstone (with Limonite/Goethite)

Ferruginous Sedimentary Rock (contains Limonite FeO(OH)·nH2O and Hematite Fe2O3)

Chert (specifically Black Chert / Flint)

Silicon Dioxide (SiO2)

Chert (Yellow or Tan Chert)

Silicon Dioxide (SiO2)

Chert (often called Flint for darker varieties)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Bauxite

Bauxite (Al2O3·2H2O)

Coquina

Bioclastic Limestone (Calcium Carbonate, CaCO3)

Chalk (Sedimentary Pebble)

Calcium Carbonate (CaCO3) - Biogenic Limestone

Sandstone

Arenite (primarily SiO2)

Coquina

Bioclastic Limestone (composed primarily of CaCO3)

Chert (Nodule)

Silicon Dioxide (SiO2)

Oolitic Limestone / Fossiliferous Chert

Oolitic Limestone (CaCO3) / Silicified Limestone

Limestone (specifically Grainstone or Micrite)

Calcium Carbonate (CaCO3)

Limestone (specifically Crushed Limestone/Calcictic)

Calcium Carbonate (CaCO3)

Sandstone (Quartzose)

Arenite (SiO2 based)

Sandstone

Arenite (composed primarily of SiO2)

Common Opal

Hydrated silica (SiO2 " nH2O)

Fossilized Gastropod in Chert/Limestone

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

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

Zebra Jasper (Zebra Stone)

Silicon Dioxide (SiO2) with iron oxide and manganese inclusions

Chert (specifically a Worked Flint/Knapped Flake)

Chert / Flint (Microcrystalline Quartz, SiO2)

Chert (specifically Pink Chert or Jasperized Chert)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Red Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Chert (Arrowhead/Tool variety)

Microcrystalline Quartz (SiO2)

Chert / Chalcedony (likely carnelian or flint variety)

Silicon Dioxide (SiO2)

Oyster Shell (Aragonite/Calcite)

Calcium Carbonate (CaCO3)

Red Chert (Jasper)

Chert / Microcrystalline Quartz (SiO2)

Chalk

Calcium Carbonate (CaCO3)

Fossiliferous Limestone (with Coralline Inclusions)

Calcium Carbonate (CaCO3)

Polychrome Jasper (Desert Jasper)

Silicon Dioxide (SiO2) with iron and mineral inclusions

Jasper (Red/Yellow)

Silicon Dioxide (SiO2) with impurities

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Quartz Geode

Silicon Dioxide (SiO2)

Jasper (likely Polychrome or Desert Jasper)

Silicon Dioxide (SiO2) with impurities

Rainbow Hematite (Man-made/Treated)

Tumbled Hematite with Titanium/Anodized coating (Iron(III) oxide, Fe2O3)

Emerald

Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities

Banded Calcite (variety Honey Calcite / Chocolate Calcite)

Calcium Carbonate (CaCO3)

Desert Rose (Gypsum Variety)

Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O