Sedimentary Rock (Technically Chert, A Microcrystalline Quartz)

Blue Chalcedony

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Banded Agate (Tumbled)

Agate (Variety of Chalcedony/Quartz), SiO2

Quartz Veinated Sandstone or Siltstone

Silicon Dioxide (SiO2) within a clastic sedimentary matrix

Quartz

Silicon Dioxide (SiO2)

Sandstone (likely Quartz Sandstone)

Arenite (SiO2 based)

Quartz (specifically Clear Quartz or Rock Crystal)

Silicon Dioxide (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Sandstone (Quartzose Pebble)

Clastic Sedimentary Rock (Litharenite/Quartz arenite)

Sandstone (with potential Arkose/Lithic characteristics)

Arenite (Sedimentary rock composed of sand-sized grains)

Chert (often called Flint)

Chert (Silicon Dioxide, SiO2)

Yellow Quartzite (River Pebble)

Quartzite (SiO2)

Chert (variations include Flint/Jasper)

Chert (Silicon Dioxide, SiO2)

Quartzite with Iron Hydroxide Staining

Quartzite (primarily SiO2) with Limonite/Goethite staining

Sandstone

Arenite (primarily Quartz, SiO2)

Quartz (Clear / Rock Crystal)

Silicon Dioxide (SiO2)

Picture Jasper

Silicon Dioxide (SiO2)

Ocean Jasper (Orbicular Jasper)

Spherulitic Chalcedony (SiO2)

Sandstone (likely Iron-rich or Arkosic)

Arenite (SiO2 with FeO(OH) or Fe2O3 staining)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Carnelian

Carnelian (Microcrystalline Quartz, SiO2)

Chert / Flint

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Conglomerate

Conglomerate (clastic sedimentary rock)

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 staining)

Quartz

Quartz (Silicon Dioxide - SiO2)

Limestone (specifically Iron-stained or Argillaceous Limestone)

Calcium Carbonate (CaCO3) with Iron Oxide (Fe2O3) impurities

Limestone

Limestone (Calcium Carbonate - CaCO3)

Limestone (Grey and White specimens)

Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Limestone

Calcite (CaCO3)

Quartzite Pebble

Quartzite (principally SiO2)

Quartz Geode (Cracked Open)

Quartz (Silicon Dioxide - SiO2)

Agate (Moss or Banded Agate variety)

Agate (Silicon Dioxide - SiO2)

Green Quartzite (with Fuchsite)

Quartzite with Muscovite variety Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)

Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)

Sandstone (likely Quartzose Sandstone)

Arenite (primarily SiO2)

Brown Antique Granite

Anorthosite (Technically a plutonic rock composed mainly of plagioclase feldspar)

Chert (Jasper variation)

Chert (Silicate mineral, SiO2)

Chert (Flint Nodular)

Chert (Silicon dioxide, SiO2)

Sandstone (Quartzose)

Sandstone (clastic sedimentary rock, primarily SiO2)

Quartz (likely Herkimer Diamond style)

Silicon Dioxide (SiO2)

Sandstone (likely Quartzose Sandstone)

Arenite (composed primarily of SiO2)