Blue Chalcedony
Chalcedony (SiO2)
Category
Browse sedimentary (formed from silica deposits) specimens identified by the Rock Identifier community.
Blue Chalcedony
Chalcedony (SiO2)
Quartz (Chert/Chalcedony variety)
Silicon Dioxide (SiO2)
Agate (Turtle Carving)
Agate (Cryptocrystalline variety of Silica, SiO2)
Opal
Hydrated silica (SiO2 · nH2O)
Chert (Flint variety)
Silicon Dioxide (SiO2)
Chert
Silicon Dioxide (SiO2)
Yellow Jasper (Chert)
Silicon Dioxide (SiO2)
Red Jasper
Microcrystalline Quartz (SiO2)
Jasper
Cryptocrystalline quartz (SiO2)
Chert / Jasper
Silicon Dioxide (SiO2)
Bamboo Leaf Jasper
Silicified Siltstone or Jasper (SiO2)
Jasper
Microcrystalline Quartz (SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Leopard Skin Jasper
Microcrystalline Quartz (SiO2) with mineral impurities
Jasper
Microcrystalline quartz (SiO2)
Jasper
Microcrystalline Quartz (SiO2) with iron oxide impurities
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Quartz (Jasper / Chert)
Silicon Dioxide (SiO2)
Jasper
Microcrystalline quartz (SiO2)
Tumbled carnelian (red-orange chalcedony)
Carnelian, a microcrystalline variety of quartz; SiO₂
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
Fossilized Bryozoan
Phylum Bryozoa
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
Chalcedony (Common Opal variant)
Silicon dioxide (SiO2) with microcrystalline structure
Chert
Silicon dioxide (SiO2)
Chert
Microcrystalline Quartz (SiO2)
River Gravel (Quartzite and Chert pebbles)
Silicon Dioxide (SiO2)
Agate
Silicon Dioxide (SiO2)
Likely rough opal
Hydrated amorphous silica (SiO₂·nH₂O), probably common opal; the image is insufficient to confirm precious opal
Fossilized Echinoid (Sea Urchin) or Brachiopod
Echinoidea / Invertebrate Fossil
Red Jasper
SiO2
Milky quartz (likely quartz vein fragment)
Quartz, silicon dioxide (SiO₂)
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Common Opal
Hydrated Silica (SiO2·nH2O)
Quartz (Agate/Jasper pebble)
Silicon Dioxide (SiO2)
Jasper
Microcrystalline Quartz (SiO2)
Imperial Jasper
Microcrystalline Quartz (Chalcedony), SiO2
Yellow Chert (Jasper)
Chalcedony (SiO2) with iron oxide inclusions
Polished gray pebble
Likely quartz-rich chert or fine-grained quartzite; exact identification is uncertain from the photograph
Red Jasper
Silicon Dioxide (Microcrystalline Quartz), SiO2
Carnelian
Silicon Dioxide (Chalcedony variety), SiO2