Sedimentary Rock (Technically A Microcrystalline Quartz Mineral Aggregate)

Veined Pebble (Septarian or Quartz-Veined Chert/Basalt)

Silicon Dioxide (SiO2) veins in matrix

Jasper Pebble

Microcrystalline Quartz (SiO2)

Chert (specifically a weathered Chert nodule or fragment)

Chert; Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Quartz (chalcedony variety) or Limestone with Quartz Veins

SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)

Chert (specifically Flint or Jasper variant)

Chert (Siliceous rock composed of microcrystalline Quartz, SiO2)

Beach Pebble (Quartzite / Sandstone)

Quartz-rich sedimentary or metamorphic rock pebble

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Chalcedony / Quartz Nodule (Agate Pebble)

Silicon Dioxide (SiO2)

Quartz Geode (likely within Limestone or Dolomite matrix)

Quartz (SiO₂)

Polished dendritic agate or jasper pebble

Microcrystalline quartz (SiO₂), likely chalcedony with iron-oxide inclusions

Chert with Quartz Vein

Microcrystalline Quartz (SiO2) with Macrocrystalline Quartz

River Stones (Quartzite and Sandstone)

Quartzite / Sedimentary Rock (SiO2 dominant)

Moss Agate Sphere

Silicon Dioxide (SiO2) with inclusions

Sandstone with Quartz Vein

Arenite with Quartz (SiO2) Infilling

Blue Chalcedony (likely dyed Agate)

Silicon Dioxide (SiO₂)

Gravel and Sand Aggregate

Unconsolidated Clastic Sediment

Yellow Jasper

Silicon Dioxide with Limonite/Goethite inclusions (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (specifically Yellow or River Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Polished chalcedony with iron-oxide cap (probable carnelian/agate)

Microcrystalline quartz, SiO₂, with hematite/goethite inclusions

Polished/tumbled brown jasper

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide inclusions

Chert Nodule / Ironstone Concretion

Microcrystalline Quartz (SiO2) with Iron Oxides

River Pebble (Quartz/Chert)

Silicon Dioxide (SiO2)

Small pale stone, likely quartzite or limestone fragment

Indeterminate; possible quartzite (mostly SiO₂) or calcitic limestone (CaCO₃)

Dendritic Chert

Silicon Dioxide with Manganese Oxide Inclusions (SiO2 + MnO2)

Banded Pebble (Metamorphic Slate or Gneiss with Quartz Veining)

Metamorphic Rock with Quartz/Calcite Veins

Dalmatian Jasper

Peralkaline Quartz-Feldspar Rock with Arfvedsonite

Tumbled cream-colored stone, possibly quartz or calcite

Indeterminate from photograph; likely microcrystalline quartz (SiO₂) or calcite (CaCO₃)

Quartz Sandstone

Quartz Arenite

Common Opal with Host Rock

Opal (Hydrated silica, SiO2·nH2O)

Jasper-rich breccia (likely iron-stained jasper)

Silicified breccia composed mainly of microcrystalline quartz (SiO₂), with hematite/goethite and possibly iron-rich clay minerals

Jasper with Quartz Druzy

Silicon Dioxide (SiO2)

Limestone with Calcite Veins

Calcium Carbonate (CaCO3)

Grape Agate (Amethystine Chalcedony)

Silicon Dioxide (SiO2) with impurities

Chert (Nodule/Pebble)

Chert (Silicon Dioxide, SiO2)

Quartz (Milky Quartz / Quartzite)

Silicon Dioxide (SiO2)

Dalmatian Jasper

Dalmatian Stone (comprised of Feldspar, Quartz, and Arfvedsonite)

Tumbled jasper (likely brecciated or common jasper)

Jasper, opaque microcrystalline quartz (SiO₂) with iron-oxide impurities

Chert Pebble

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sandstone (Pebble)

Sandstone

Beach Pebbles and Quartz Aggregates

Quartz / Calcite Beach Pebbles (SiO2 / CaCO3)