Sedimentary Rock (Technically Chert, A Microcrystalline Quartz)

Dalmatian Stone (Dalmatian Jasper)

Peralkaline Quartz-Feldspar Rock with Arfvedsonite

Moss Agate and Druzy Quartz Carving

Cryptocrystalline Silica (SiO2) with impurities

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Yellow Jasper / Chert

Jasper (Silica/Quartz) - SiO2

Quartzite

Quartzite (SiO2)

Lapis Lazuli (Tumbled Specimen)

Lapis Lazuli (Aggregate rock containing Lazurite: (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2)

Quartz in Matrix (possibly Basalt or Siltstone host)

Silicon Dioxide (SiO2) in Host Rock

Petrified Wood

Silicified Wood (SiO2)

Blue Chalcedony

Silicon Dioxide (SiO2)

Jasper with Quartz inclusion

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Jasper (Chocolate or Brown Jasper)

Silicon Dioxide (SiO2)

Druzy Quartz (on Quartzite or Chert)

Silicon Dioxide (SiO2)

Dalmatian Stone

Peralkaline Feldsphathic Igneous Rock

Red Jasper

Jasper (Silicon Dioxide) - SiO2

Chert (often called Flint when dark or found in chalk)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Green Jasper

Silicon Dioxide (SiO2) with impurities

Zebra Jasper

Silicon Dioxide (SiO2) - Macro-crystalline Quartz/Chert with impurities

River Pebble (Quartz/Jasper)

Silicon Dioxide (SiO2)

Red Brecciated Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Dendritic Agate

Silicon Dioxide (SiO2) with manganese/iron inclusions

Agate

Agate (Microcrystalline Quartz, SiO2)

Sandstone with Quartz Vein

Arenite with Quartz (SiO2) Infilling

Shale or Argillite

Shale (sedimentary) / Argillite (metamorphic)

Concretion with Quartz Veining

Septarian Concretion (CaCO3 / SiO2)

Chert (Flint)

Chert (Cryptocrystalline Quartz, SiO2)

Green Jasper

Silicon Dioxide (SiO2) with impurities

Geode with Quartz/Chalcedony

Silicon Dioxide (SiO2)

Amygdaloidal Rhyolite (often called Lake Superior Agate relative)

Rhyolite with Calcite/Quartz amygdules (SiO2 and secondary minerals)

River Chalcedony / Agate

Chalcedony (Silicon Dioxide, SiO2)

Chert (Septarian Concretion/Nodule)

Microcrystalline silica (SiO2) with carbonate mineral veining

Chert (Jasper variety) with Iron Oxide staining

Cryptocrystalline Quartz (SiO2) with Goethite/Limonite impurities

Red Jasper (Quartz)

Silicon Dioxide (SiO2) with Iron impurities

Agate

Chalcedony (cryptocrystalline variety of Quartz, SiO2)

Jasper (Multi-color Chert)

Silicon dioxide (SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Dendritic Agate (specifically Orange/Tumbled)

Silicon Dioxide (SiO2) with Oxide Inclusions

Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Ocean Jasper

Orbicular Jasper (Silicon Dioxide - SiO2)

Chert (often called Flint or Jasper when pigmented)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Sandstone

Quartz Sandstone (predominantly)