Fossilized Shark Tooth (Cretaceous to Neogene)
Elasmobranchii dental fossil (likely Squalicorax or similar species)
mineral (biogenic replacement)
Category
Sedimentary (Formed From Silica Deposits)
Browse sedimentary (formed from silica deposits) specimens identified by the Rock Identifier community.
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Chalcedony (Agate/Carnelian)
Cryptocrystalline Silicon Dioxide (SiO2)
mineral
Chert / Flint
Silicon Dioxide (SiO2)
sedimentary
Jasper / Chert (river tumbled)
Microcrystalline Quartz (SiO2)
sedimentary
Chert / Flint
Silicon Dioxide (SiO2)
sedimentary
Likely quartz-rich stone or shell fragment
Uncertain; possibly quartz (SiO₂) or a calcareous shell fragment (CaCO₃)
mineral
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint/Jasper)
Silicon Dioxide (SiO2)
sedimentary
River Pebble (Grey Quartzite / Sandstone Gravel)
Quartz-rich Sedimentary / Metamorphic River Pebble
sedimentary
Jasper
Silicon dioxide (SiO2)
sedimentary
Chert (Chalcedony/Agate Pebble)
Cryptocrystalline Silica (SiO2)
sedimentary
Tumbled quartz-rich pebble
Microcrystalline quartz (SiO₂), possibly weathered chert or chalcedony
mineral
Shark Tooth Fossil
Selachii fossil
fossil
Chert (Chalcedony)
Cryptocrystalline Quartz (SiO2)
sedimentary
Carnelian
Carnelian, orange-red variety of chalcedony (microcrystalline quartz, SiO₂)
gemstone
Black Opal
Amorphous hydrated silica (SiO2 nH2O)
mineral
Jasper
Silicon Dioxide (SiO2) with impurities
sedimentary
Chert (Flint Nodular)
Silicon Dioxide (SiO2)
sedimentary
Chert (Green variety)
Microcrystalline Quartz (SiO2)
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2)
mineral
Chert (Jasper/Agate variety)
Microcrystalline quartz (SiO2)
sedimentary
Milky quartz
Quartz (silicon dioxide, SiO₂)
mineral
Jasper
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Chert (Flint) Pebble
Microcrystalline Quartz (SiO2)
sedimentary
Agate
Silicon Dioxide (Chalcedony), SiO2
sedimentary
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Chalcedony Pebble
Cryptocrystalline Quartz (SiO2)
mineral
Chert / Flint
Chert (Cryptocrystalline Quartz, SiO2)
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper)
Cryptocrystalline Quartz (SiO2)
sedimentary
Rounded quartz-rich pebble
Chert or quartzite pebble (indeterminate from image)
sedimentary
Yellow Chert (Cherty Pebble)
Silicon Dioxide (SiO2)
sedimentary
Chert (likely chalcedony-rich flint)
Microcrystalline quartz, SiO₂ (quartz/chalcedony)
sedimentary
Chert (Nodular Chert)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Chert / Flint
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Pebble)
Microcrystalline silica (SiO2)
sedimentary
Chert or flint fragment
Microcrystalline quartz (SiO₂), commonly chalcedony with cryptocrystalline quartz
sedimentary
Chert (Jasper and Chalcedony)
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper) Pebble
Microcrystalline Quartz (SiO2)
sedimentary
Chalcedony (Blue/Grey Lace Agate)
Silicon Dioxide (SiO2)
mineral
Jasper (Wonderstone/Banded Jasper)
Silicon Dioxide (SiO2) with iron oxide impurities
sedimentary (chemical/biological origin) or volcanic-related metamorphic
Grey Banded Agate
Silicon Dioxide (SiO2)
sedimentary