Sedimentary Rock (Technically A Microcrystalline Quartz Mineral Aggregate)

Red Jasper with Quartz

Microcrystalline Quartz (SiO2)

Yellow chalcedony or quartz fragment

Microcrystalline quartz, SiO₂ (tentative; possibly iron-stained chalcedony)

Moss agate (likely dendritic/chalcedony slab)

Cryptocrystalline quartz, SiO₂, with green amphibole or chlorite inclusions

River Pebble (likely Quartzite or Chert)

Silicon Dioxide (SiO2) crystal conglomerate

Quartz Geode Segment

Crystalline Silicon Dioxide (SiO2)

Sandstone Pebble

Sedimentary Rock (Quartzose Sandstone)

Weathered quartz-rich rock, likely chert or quartzite

Microcrystalline quartz (SiO₂), possibly with iron-oxide staining

Chert / Chalcedony Nodules

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Limestone or Sandstone Cobble

Sedimentary rock (Calcium carbonate or Quartz based)

Snowflake Obsidian

Volcanic Glass with Spherulite Inclusions (primarily SiO2)

Quartz / Calcite Pebble

SiO2 (Quartz) or CaCO3 (Calcite)

Quartz

Silicon Dioxide (SiO2)

Weathered quartz-rich rock fragment

Likely quartz-bearing sandstone or granitic rock; exact identification is uncertain from the image

Dalmatian Stone

Peralkaline igneous rock containing quartz, feldspar, and arfvedsonite

Quartz-Veined Sandstone

Quartz-veined Arenite

Chert (Iron-Stained)

Microcrystalline Quartz (SiO2)

Orbicular Jasper

Silicon Dioxide (SiO2)

Dendritic Agate

Silicon Dioxide (SiO2) with manganese/iron inclusions

Weathered iron-rich chert or siliceous breccia

Microcrystalline quartz (SiO₂), likely with iron oxides and minor clay minerals

Tumbled yellow jasper or chert

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

River Pebble (Quartz-rich)

Silicon Dioxide (SiO2) with impurities

Chert (Brecciated Chert)

Silicon Dioxide (SiO2)

Yellow Jasper

Silicon Dioxide (SiO2 with iron oxide inclusions)

Chert (within Limestone)

Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)

Chert (Flint Nodule)

Microcrystalline and Cryptocrystalline Quartz (SiO2)

Quartz Geode (partially filled/solid)

Silicon Dioxide (SiO2)

Vein-filled Sedimentary Rock

Silicified sedimentary rock with quartz/calcite vein

Quartz Geode in Chert/Limestone Matrix

Silicon Dioxide (SiO2) within Sedimentary Host Rock

Red jasper (likely iron-rich chert)

Microcrystalline quartz (SiO₂) colored by hematite/goethite

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Beach Pebble / Agate-bearing Chert Pebble

Microcrystalline Quartz (SiO2) with Inclusion Minerals

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO2)

Gneiss with Quartz Vein

Metamorphic Gneiss with Quartz (SiO2) and Feldspar Injection

Chert (River Pebble)

Microcrystalline silicon dioxide (SiO2)

Limestone Riprap

Sedimentary Calcium Carbonate (CaCO3)

Jasper with Quartz Vein

Microcrystalline quartz (SiO2) with impurities

Polished jasper or iron-stained chert

Microcrystalline quartz (SiO₂), commonly chalcedony with iron-oxide staining

Chert Pebble

Microcrystalline Quartz (SiO2)

Green Chert (Jasper / Flint)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Tumbled jasper

Microcrystalline quartz (SiO₂), commonly with iron-oxide impurities

Chert (Nodule)

Microcrystalline or cryptocrystalline Quartz (SiO2)