Sedimentary (Cryptocrystalline Silica)

Agatized Chert / Chalcedony

Silicon Dioxide (SiO2)

Chert (specifically Chalcedony/Flint variant)

Silicon Dioxide (SiO2)

Chert (with Quartz Veining)

Chert (formula: SiO2)

Chalcedony on Matrix

Silicon Dioxide (SiO2)

Chert (Flint)

Chert (SiO2)

Flint (within Limestone matrix)

Silicon dioxide (SiO2)

Chert (varietal: Flint/Jasper mix)

Hydrous Silica (SiO2)

Chert (Chert / Flint)

Silicon dioxide (SiO2) - Microcrystalline quartz

Chert (varieties include Flint and Jasper)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Arrowhead variety)

Chert (SiO2)

Agate with Druzy Quartz

Silicon Dioxide (SiO2)

Mookaite Jasper

Silicified Radiolarite (SiO2)

Chalcedony (Agate/Jasper mix in host rock)

Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)

Chert (Tan/Grey variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Field-collected Arrowhead-shaped Fragment)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (often found as Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (variously known as Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (often called Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Yellow/Tan variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (and/or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Banded Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Chalcedony)

Microcrystalline Quartz (SiO2)

Black Jasper

Jasper (Silicon Dioxide, SiO2)

Chert Pebble (Jasperoid/Flint)

Silicon Dioxide (SiO2) - cryptocrystalline quartz

Chert / Chalcedony (likely carnelian or flint variety)

Silicon Dioxide (SiO2)

Chert Pebble/Nodule

Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)

Chert (Black Chert / Flint)

Silicon Dioxide (SiO2)

Chert (Pebble)

Microcrystalline silica (SiO2)

Chalcedony

Silicon Dioxide (SiO2)

Chert (specifically Gray/Blue-Gray Chert)

Chert (SiO2)

Chert (Common Opal variant)

Microcrystalline Quartz (SiO2)

Chert (often called Flint or River Stone)

Chert (Microcrystalline Silicon Dioxide, SiO2)

Carnelian (a variety of Chalcedony)

SiO2 (Silicon Dioxide) - Cryptocrystalline Quartz

Chert (Field-collected specimen)

Chert (Crystalline Silica, SiO2)

Banded Agate (specifically Lake Superior Agate or similar)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Blue Chalcedony

Silicon Dioxide (SiO2)

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (variations include Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (often called Flint)

Cryptocrystalline Quartz (SiO2)