Blue Dyed Agate Geode
Chalcedony (cryptocrystalline Quartz), SiO2
Category
Browse sedimentary rock (technically a variety of chalcedony) specimens identified by the Rock Identifier community.
Blue Dyed Agate Geode
Chalcedony (cryptocrystalline Quartz), SiO2
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Conglomerate
Conglomerate (Detrital sedimentary rock)
Sandstone (likely River-tumbled Picture Sandstone)
Arenite (predominantly SiO2 with iron oxide impurities)
Sandstone (Micaceous Sandstone)
Arenite (SiO2 with KAl2(AlSi3O10)(OH)2 inclusions)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Anthracite Coal
Anthracite (a variety of coal, predominantly carbon)
Sandstone (lithic wacke/arenite)
Clastic sedimentary rock (primarily SiO2)
Sandstone (Red/Brown Variety)
Arenite (SiO2 with iron oxide impurities)
Red Sandstone
Sandstone (principally Quartz with Iron Oxide coating)
Leopard Skin Jasper
Silicon Dioxide (SiO2) with various inclusions
Tiffany Stone
Fluoritized Opal Beryllium Tuff (composed of Fluorite; CaF2, Opalized SiO2, Bertrandite, Chalcedony, and Quartz)
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite/Iron oxide impurities
Conglomerate
Conglomerate (SiO2, Al2O3, Fe2O3, CaCo3)
Obsidian
Obsidian (principally SiO2 - Silicon Dioxide)
Conglomerate
Conglomerate (clastic sedimentary rock)
Carnelian (Red Chalcedony)
Silicon Dioxide (SiO2)
Chert (with Quartz Vein)
Chert (Siliceous sedimentary rock, predominantly Microcrystalline Quartz SiO2)
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Obsidian
Volcanic Glass (SiO2)
Sandstone (Iron-stained)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
Sandstone (Quartzite-rich Cobble)
Clastic sedimentary rock (primarily SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Chert (Jasper)
Silicon dioxide (SiO2)
Chert (varieties: Flint or Chalcedony)
Microcrystalline silica (SiO2)
Chert (variations include Flint or Jasper)
Cryptocrystalline Quartz (SiO2)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Banded Agate
Agate (Cryptocrystalline Quartz, SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Chert (Jasper/Flint variation)
Chert (SiO2)
Montana Moss Agate
Chalcedony (SiO2) with Manganese/Iron oxide inclusions
River Pebbles and Quartz
Mixed Igneous, Sedimentary, and Metamorphic Rocks (Silicon Dioxide SiO2 dominant)
Conglomerate
Conglomerate (Sedimentary Clastic Rock)
Banded Agate (variety of Chalcedony)
Agate (SiO2)
Banded Agate
Sedimentary Cryptocrystalline Quartz (SiO2)
Shale
Shale (fine-grained clastic sedimentary rock)
Chert (Jasper variety)
Cryptocrystalline quartz (SiO2)
Chert (Green variety)
Silicon Dioxide (SiO2)
Jasper (likely river-tumbled)
Jasper (Silica/Silicon Dioxide, SiO2)
Mixed Gemstone Bracelet
Mixed natural minerals and rocks (e.g., Rhodonite, Malachite, Sodalite, Rose Quartz, Black Tourmaline, Quartz/Chalcedony variants)
Mookaite Jasper
Radiolarite (Silica-rich sedimentary rock featuring Hematite and Goethite)