Sedimentary

Chert (Gravel pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Chert Nodule)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (specifically Yellow or River Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Pink Granite

Phaneritic Plutonic Felsic Igneous Rock (Granite)

Petrified Wood

Silicified Wood (primarily SiO₂ / Silicon Dioxide)

Calcite with iron staining

Calcium Carbonate (CaCO3)

Petrified Wood

Silicified Wood (SiO2)

Granite Cobble

Phaneritic Felsic Igneous Rock (Granite)

Milky Quartz

Silicon Dioxide (SiO2)

Limonite (Iron Stone)

Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O

Quartz-Veined Mudstone

Argillaceous Mudstone with Quartz Veining

Chert (Arrowhead Fragment)

Chert / Microcrystalline Silicon Dioxide (SiO2)

Siltstone Pebble

Siltstone

Petoskey Stone

Hexagonaria percarinata (Fossilized Rugose Coral)

Petoskey Stone

Hexagonaria percarinata (Fossilized Rugose Coral)

Fossilized Coral (Petoskey Stone or similar)

Hexagonaria percarinata (Fossilized Rugose Coral)

Fossiliferous Limestone (Crinoidal)

Calcite-bearing bioclastic packstone (CaCO3)

Banded Chert

Microcrystalline Quartz (SiO2)

Chert (Dark Variety / Flint)

Silicon Dioxide (SiO2)

Chert (often called Flint when dark)

Microcrystalline silicon dioxide (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Chert (Field Stone)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Ironstone Concretion / Limonite Node

Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O) with Goethite/Hematite

Chert (and/or Flint)

Microcrystalline Quartz (SiO2)

Chert (Jasper-bearing)

Microcrystalline silica (SiO2) with iron oxide inclusions

Fossil Brachiopod Cast (Atrypa species)

Phylum Brachiopoda, Class Rhynchonellata, Order Atrypida

Bloodstone (Heliotrope)

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Chert (specifically Jasper or Brown Chert node)

Microcrystalline Quartz (SiO2)

Chert (variously identified as Flint)

Microcrystalline Quartz (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Moqui Marble

Ironstone Concretion (Goethite/Hematite shell with Sandstone core)

Chert (with Quartz Veining)

Microcrystalline silicon dioxide (SiO2)

Poppy Jasper

Jasper (variety of Chalcedony), SiO2 (Silicon Dioxide)

Yellow Jasper

Silicon Dioxide (SiO2) - variety of Chalcedony

Red Jasper

Jasper (Silicon Dioxide, SiO2)

Bauxite

Bauxite (mixture of hydrous aluminum oxides: Al(OH)3 & AlO(OH))

Chert (Nodule)

Chert (mainly Microcrystalline or Cryptocrystalline Quartz, SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Ironstone Concretion (Moqui Marble Type)

Goethite/Hematite-cemented Sandstone Concretion

Chert (Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Flint or Gray Chert)

Silicon Dioxide (SiO2)