Sedimentary (Secondary Classification: Cryptocrystalline Quartz)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Chert (and/or Chalcedony)

Silicon dioxide (SiO2)

Plume Agate

Silicon Dioxide (SiO2)

Quartz Vein in Host Rock

Quartz (SiO2) in Mafic or Sedimentary Matrix

Mixed Chalcedony and Jasper Bracelet (possibly 'Ocean Jasper' or similar banded variety for brown beads, and blue/grey Chalcedony for the translucent beads)

Chalcedony (SiO2), Jasper (SiO2 with impurities)

Dendritic Agate

Silicon Dioxide with Manganese or Iron Oxide inclusions (SiO2 + Mn/Fe)

Mica Schist with Quartz

Mica-Quartz Schist (Muscovite subclass)

Quartz / Common Opal

Silicon Dioxide (SiO2)

Sand (Construction Grade)

Unconsolidated siliciclastic sediment (primarily SiO2)

Onyx Marble (also commonly called Onyx)

Calcite (CaCO3), often with other mineral impurities

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Quartz (Milky or White Quartz)

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO₂)

Agate / Banded Chalcedony

Agate (Silicon Dioxide / SiO2)

Green Aventurine

Silicon dioxide (SiO2) with fuchsite inclusions

Agate

Silicon Dioxide (SiO2) - variety: Chalcedony

Banded Agate (Agatized Geode Slice)

Silicon Dioxide (SiO₂)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz Geode/Druzy Quartz

Quartz (SiO₂)

Quartz (Milky or White Quartz)

Silicon Dioxide (SiO2)

Carnelian

Carnelian (a variety of Chalcedony, SiO2)

Jasper (Banded Jasper)

Silicon Dioxide (SiO2) with impurities

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Sand Grain (Silica/Quartz Grain)

Silicon Dioxide (SiO2)

Dyed Agate

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Chert (Flint)

Silicon Dioxide (SiO2)

Red Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Quartz

Silicon dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Jasper (Iron-stained Chalcedony)

SiO2 with Fe2O3 (Iron Oxide) impurities

Chert (with Limestone matrix)

Chert (Silica: SiO2)

Agate (Chert/Chalcedony)

Silicon Dioxide (SiO2)

Sandstone Geode (Unbroken)

Siliciclastic sedimentary rock (primarily Quartz)

Banded Agate (specifically Sardonyx)

Silicon Dioxide (SiO2) - variety of Chalcedony/Quartz

Conglomerate with Quartzite Pebbles

Clastic sedimentary rock (Conglomerate)

Conglomerate

Conglomerate (Sedimentary Clastic Rock)

Chert (often called Flint or Jasper)

Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)

Chert (specifically Flint or Jasper variant)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)