Sedimentary Rock (Specifically A Chemical Sedimentary Rock, Or A Chert If Considered Purely Mineral Aggregate)

Chert (Quartz Variety)

Silicon Dioxide (SiO2)

Chert (specifically Iron-stained River Cobble)

Silicon Dioxide (SiO2)

Chert (Nodule)

Chert (Cryptocrystalline Silica, SiO2)

Limestone (specifically Dolomitic Limestone)

Calcium Magnesium Carbonate (CaMg(CO3)2)

Chert (Flint)

Chert (̑SiO2)

Travertine (Tufa)

Chemical Limestone (CaCO3)

Chert (Flint)

Silicon Dioxide (SiO2)

Banded Chert

Microcrystalline Quartz (SiO2)

Banded Chert

Silicon Dioxide (SiO2)

Chert (Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Chert (Tan/Yellow variety)

Microcrystalline quartz (SiO2)

Granodiorite

Phaneritic intrusive igneous rock (intermediate composition)

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (often called Flint)

Chert (Microcrystalline or cryptocrystalline Silica, SiO2)

Chert (specifically Green Chert/Jasper)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chert Pebble

Chert (composed primarily of Microcrystalline Quartz, SiO2)

Stromatolite

Laminated biogenic sedimentary structure (formed by Cyanobacteria)

Sandstone (Quartzose Pebble)

Arenite (SiO2)

Chert (often called Flint in various colors)

Silicon Dioxide (SiO2)

Chert

Silicon dioxide (SiO2)

Quartz-rich rock fragment, possibly chert or weathered quartz

Microcrystalline quartz (SiO₂), tentative identification

Chert (Common Opal or Flint variant)

Microcrystalline Quartz (SiO2)

Chert (Pebble)

Silicon Dioxide (SiO2)

Quartzite (or Chert/Flint gravel)

Quartzite (SiO2 with iron oxide inclusions)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert

Silicon Dioxide (SiO2)

Chert (Flint)

Microcrystalline quartz (SiO2)

Chert (Jasper variety)

Microcrystalline Quartz (SiO2)

Chert

Microcrystalline or cryptocrystalline quartz (SiO2)

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert (Yellow Jasper)

Microcrystalline Quartz (SiO2)

Chert (Brown Variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Dendritic Agate or Manganese Nodule in Chert/Limestone

Silicon Dioxide (SiO2) with Manganese Oxide (MnO2) inclusions

Chert (Flint)

Cryptocrystalline Silica (SiO2)

Weathered vesicular basalt (likely amygdaloidal basalt)

Basalt, composed mainly of plagioclase feldspar, pyroxene, and altered olivine; cavities may contain secondary zeolite, calcite, or silica

Chert

Microcrystalline Quartz (SiO2)

Banded Iron Formation (BIF)

Banded Iron Formation

Chert/Flint Nodule

Microcrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Flint

SiO2 (Cryptocrystalline Quartz / Chert)

Chert

Chert (Microcrystalline Quartz, SiO2)