Limestone

Chert

Microcrystalline Quartz (SiO2)

Chert (Jasper variety)

Silicon Dioxide (SiO2) with iron oxide impurities

Fossiliferous Chert (Chert with Crinoid Stem Impression)

Chert (SiO2) with fossil Anthozoan or Crinoid columnals

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Chert (often called Flint)

Chert (Microcrystalline or cryptocrystalline Silica, SiO2)

Chert (specifically Gray Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Green variety)

Chert (Silicon Dioxide, SiO2)

Travertine (Ceramic Tile)

Terrestrial Sedimentary Rock / Calcium Carbonate (CaCO3)

Chert (varieties include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (varieties: Flint or Jasper)

Microcrystalline Quartz (SiO2)

Quartz Geode

Silicon Dioxide (SiO2) within a geode

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

Chert (Fossiliferous)

Silicon dioxide (SiO2)

Chert (Flint nodule)

Silicon dioxide (SiO2)

Banded Chert

Microcrystalline Quartz (SiO2)

Chert (Chert Nodule)

Microcrystalline quartz (SiO2)

Chert (Chalky/Gray Variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Geode with Quartz/Chalcedony

Silicon Dioxide (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Chert (varieties include Flint and Jasper)

Silicon Dioxide (SiO2) / Microcrystalline Quartz

Chert (Flint)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chert Nodule

Microcrystalline Quartz (SiO2)

Chert (Flint)

Chert (Silicon Dioxide, SiO2)

Chert (with Iron Staining)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically as a lithic artifact/projectile point)

Chert (Silicon dioxide, SiO2)

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Fossil Coral (likely Favosites or Honeycomb Coral)

Class Anthozoa, Order Tabulata, Genus Favosites

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Chert (specifically Blue Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Orthoceras Fossil Limestone

Orthoceras (extinct genus of cephalopod); Limestone matrix (CaCO3)

Yellow Chert (Jasper)

Chalcedony (SiO2) with iron oxide inclusions

Chert (Flint)

Chert (Silicon Dioxide, SiO2)

Chert / Flint

Silicon Dioxide (SiO2)

Chert (Common Chert)

Cryptocrystalline Quartz (SiO2)

Limestone with Quartz/Calcite Veins

Sedimentary Limestone (CaCO3 with SiO2 or CaCO3 intrusions)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Crinoid Fossil in Chert

Siliceous limestone with Crinoidea fossil (SiO2)

White Marble (Whiskey Stone)

Recrystallized Calcite / Marble (CaCO3)

Chert (Jasper/Flint variant)

Microcrystalline Quartz (SiO2)

Crazy Lace Agate

Silicon Dioxide (SiO2) - Chalcedony variety

Chert (Flint)

Cryptocrystalline Quartz (SiO2)