Chalcedony (Common Opal variant or Agate)
Silicon Dioxide (SiO2)
Category
Browse sedimentary (formed from silica deposits) specimens identified by the Rock Identifier community.
Chalcedony (Common Opal variant or Agate)
Silicon Dioxide (SiO2)
Brown Jasper (Tumbled)
Silicon Dioxide (SiO2) with iron oxide inclusions
Chert (Jasper/Common Opal mix)
Microcrystalline Quartz (SiO2)
Red jasper (likely iron-rich chert)
Microcrystalline quartz, SiO₂, colored mainly by hematite/goethite
Quartz Pebble
Silicon Dioxide (SiO2)
Fossil Seashell
Invertebrate fossil (Bivalvia)
River Pebble (Quartz/Chert mix)
Silicon Dioxide (SiO2) with various inclusions
Chert (Flint / Banded Chalcedony)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Jasper
Microcrystalline Quartz (SiO2)
Clear Quartz / Rock Crystal
Silicon Dioxide (SiO2)
Chert / Flint
Silicon dioxide (SiO2)
Yellow Jasper
SiO2
Jasper
Microcrystalline Quartz (SiO2)
Chert (Jasper)
Silicon Dioxide (SiO2) with impurities
Chert (specifically Flint or Common Opal variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Opal cabochon pendant
Opal, hydrated amorphous silica (SiO₂·nH₂O), likely common or precious opal
Chert
Microcrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chalcedony (Agate/Chert variety)
Silicon Dioxide (SiO2)
Shark Tooth Fossil
Vertebrate fossilized tooth (Chondrichthyes)
Chert / Flint
Microcrystalline Quartz (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Jasper
Microcrystalline Quartz (SiO2)
Chert (Flint Nodules)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Agate (Carnelian Agate with Quartz Matrix)
Silicon Dioxide (SiO2)
Chert (Jasper/Agate variant)
Microcrystalline Quartz (SiO2)
Jasper
Microcrystalline Quartz (SiO2)
Opal ring
Opal (hydrated amorphous silica, SiO₂·nH₂O)
Carnelian
Chalcedony (SiO2) with iron oxide impurities
Yellow Agate (Banded Chalcedony)
Silicon Dioxide (SiO2)
Chalcedony (Agate/Carnelian pebbles)
Cryptocrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Jasper
Silicon dioxide (SiO2)
Chert (or Flint)
Chert (cryptocrystalline quartz), SiO2
Chert/Flint Nodule
Microcrystalline Quartz (SiO2)
Botryoidal Agate / Chalcedony Geode
Silicon Dioxide (SiO2)
Chert (Jasper/Agate variety)
Silicon Dioxide (SiO2)
Chert
Cryptocrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Common Opal
Hydrated silica (SiO2 " nH2O)
Opal
Hydrated silicon dioxide (SiO2·nH2O)
Quartz Geode Fragment
Silicon Dioxide (SiO2)