Sedimentary (If Chert)

Flint in Chalk

Sedimentary nodular chert within chalk (SiO2)

Banded Chert

Chert (Silicon Dioxide, SiO2)

Breciated Chert

Brecciated Chert (Microcrystalline Quartz, SiO2)

Chert (Arrowhead Fragment)

Microcrystalline Quartz (SiO2)

Quartz or possibly Jasper/Chert. Looks like a tumbled or water-worn stone.

SiO2 (Silicon Dioxide)

River Pebble / Chert Pebble

Microcrystalline Quartz (SiO2)

River Pebble (Quartzite or Chert)

Silicon Dioxide (SiO2)

Iron-stained chert or siliceous mudstone

Microcrystalline quartz (SiO₂), likely chert with hematite/goethite staining

Mixed Gemstones and Minerals

Mixed Silicates and Oxides (Quartz/Amethyst, Aventurine, Sodalite, Chert, Jasper)

Brown quartz-rich pebble (likely chert or weathered quartzite)

Quartz (SiO₂), possibly microcrystalline quartz/chert or quartzite

Chert (Jasper)

Silicon Dioxide (SiO2)

Quartz (River Pebble) and Chert/Jasper

Silicon Dioxide (SiO2)

Quartz Druzy in Chert Pebble

Silicon Dioxide (SiO2) - Microcrystalline & Crystalline Quartz

Dalmatian Stone

Dalmatian Jasper (a misnomer) / Perthitic Igneous Rock

Rounded quartz-rich pebble

Likely chert or quartzite; predominantly microcrystalline quartz (SiO₂)

Likely quartz-rich rock fragment

Probably microcrystalline quartz (SiO₂), possibly a pale chert or quartzite fragment

Banded Chert

Microcrystalline Quartz (SiO2)

Chert (or potentially massive Quartz/Quartzite)

SiO2 (Silicon Dioxide)

White Quartz

Quartz (SiO2)

Quartz

Quartz (SiO2)

Quartz

Silicon Dioxide (SiO2)

River Pebble (Likely Chert or Fine-Grained Sandstone/Quartzite)

Siliciclastic clast (likely Chert or Quartzarenite/Quartzite pebble)

Chert Nodules in Limestone / Fault Breccia

Silicon Dioxide (SiO2) in Calcium Carbonate (CaCO3) matrix

Chert Nodule in Limestone

Chert (Microcrystalline Quartz, SiO2) and Limestone (Calcium Carbonate, CaCO3)

Chert

Microcrystalline or cryptocrystalline quartz

Flint/Chert Nodule in Limestone

Sedimentary rock containing microcrystalline quartz (SiO2) within a calcium carbonate (CaCO3) matrix

Chert (flint) fragment

Microcrystalline quartz (SiO₂), commonly called chert or flint

Chert nodules in Limestone

Microcrystalline Quartz (SiO2) in Calcium Carbonate (CaCO3) matrix

Tumbled chert or flint pebble

Microcrystalline quartz (SiO₂), likely chert

Likely green-brown jasper or iron-stained chert

Microcrystalline quartz (SiO₂), possibly iron-oxide-stained chert/jasper

Chert (likely flint)

Microcrystalline quartz, SiO₂ (chalcedony/quartz aggregate)

Weathered chert or flint fragment

Microcrystalline quartz (SiO₂), likely chalcedonic chert with iron-oxide staining

Chert with Limestone

Microcrystalline Quartz (SiO2) in Calcium Carbonate (CaCO3) matrix

Chert

Silicon dioxide (SiO2)

Chert with Limestone matrix

Microcrystalline silica (SiO2) in Calcite (CaCO3) matrix

Chert Nodules in Limestone

Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)

Tumbled quartz-rich pebble, likely jasper or chert

Microcrystalline quartz (SiO₂), possibly iron-stained jasper

Weathered chert or flint pebble

Microcrystalline quartz (SiO₂), likely chert/flint with possible carbonate or quartz vein

Chert Nodule in Limestone

Microcrystalline Silica (SiO2) within Calcium Carbonate (CaCO3)

Chert (Limonite-stained)

Microcrystalline Quartz (SiO2) with iron oxides

Brown chert (flint)

Microcrystalline quartz (SiO₂), commonly called chert; the specimen may be iron-stained

Chert Nodules in Limestone

Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)