Rock Identifier

Category

Sedimentary (Cryptocrystalline Silica)

Browse sedimentary (cryptocrystalline silica) specimens identified by the Rock Identifier community.

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

Green Banded Agate (Agate (Cryptocrystalline variety of Quartz, SiO2)) — mineral

Green Banded Agate

Agate (Cryptocrystalline variety of Quartz, SiO2)

Petrified Wood (Silicified Wood (SiO2 - Quartz/Chalcedony replacement)) — Mineral / Fossil

Petrified Wood

Silicified Wood (SiO2 - Quartz/Chalcedony replacement)

Mineral / Fossil

Thunderegg (specifically a Jasper/Agate-filled Geode nodule) (Silicon Dioxide (SiO2) within Rhyolitic Matrix) — igneous

Thunderegg (specifically a Jasper/Agate-filled Geode nodule)

Silicon Dioxide (SiO2) within Rhyolitic Matrix

Banded Agate (likely Carnelian Agate or Sardonyx) (Agate is a common name for a microcrystalline variety of Quartz (SiO₂), specifically a form of Chalcedony.) — Sedimentary Rock (technically a variety of Chalcedony)

Banded Agate (likely Carnelian Agate or Sardonyx)

Agate is a common name for a microcrystalline variety of Quartz (SiO₂), specifically a form of Chalcedony.

Sedimentary Rock (technically a variety of Chalcedony)

Lake Superior Agate (Banded Chalcedony (Silicon Dioxide / SiO2)) — mineral

Lake Superior Agate

Banded Chalcedony (Silicon Dioxide / SiO2)

Banded Agate (Tumbled) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — mineral

Banded Agate (Tumbled)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

River Stone (likely Quartzite or Chert) (Recrystallized Silicon Dioxide (SiO2)) — metamorphic

River Stone (likely Quartzite or Chert)

Recrystallized Silicon Dioxide (SiO2)

Carnelian Agate (Silicon Dioxide (SiO2) with iron oxide impurities) — Mineral

Carnelian Agate

Silicon Dioxide (SiO2) with iron oxide impurities

Banded Agate (Botswana Agate) (Silicon Dioxide (SiO2)) — mineral

Banded Agate (Botswana Agate)

Silicon Dioxide (SiO2)

Banded Agate (Pink/Peach Chalcedony) (Agate (Silicon Dioxide, SiO2)) — mineral

Banded Agate (Pink/Peach Chalcedony)

Agate (Silicon Dioxide, SiO2)

Basalt with Jasper Veining (Basaltic Rock with Cryptocrystalline Quartz (SiO2)) — igneous

Basalt with Jasper Veining

Basaltic Rock with Cryptocrystalline Quartz (SiO2)

Blue Lace Agate (Chalcedony (cryptocrystalline variety of Quartz), SiO2) — mineral

Blue Lace Agate

Chalcedony (cryptocrystalline variety of Quartz), SiO2

Banded Agate (Lace Agate) (Agate (Variety of Cryptocrystalline Quartz), SiO2) — mineral

Banded Agate (Lace Agate)

Agate (Variety of Cryptocrystalline Quartz), SiO2

Blue Dyed Agate Geode (Chalcedony (cryptocrystalline Quartz), SiO2) — mineral

Blue Dyed Agate Geode

Chalcedony (cryptocrystalline Quartz), SiO2

Shiva Lingam (Cryptocrystalline Quartz (Jasproid/Sandstone) with Iron Oxide (Fe2O3)) — sedimentary

Shiva Lingam

Cryptocrystalline Quartz (Jasproid/Sandstone) with Iron Oxide (Fe2O3)

Shiva Lingam (Cryptocrystalline Quartz (Jasper/Chalcedony) with Iron Oxide inclusions) — sedimentary

Shiva Lingam

Cryptocrystalline Quartz (Jasper/Chalcedony) with Iron Oxide inclusions

Moss Agate / Chalcedony (Silicon Dioxide (SiO2)) — mineral

Moss Agate / Chalcedony

Silicon Dioxide (SiO2)

Carnelian Agate (Chalcedony (SiO2) with iron oxide inclusions) — mineral

Carnelian Agate

Chalcedony (SiO2) with iron oxide inclusions

Botryoidal Chalcedony (Agate/Carnelian) (Chalcedony (SiO2)) — mineral

Botryoidal Chalcedony (Agate/Carnelian)

Chalcedony (SiO2)

Red Jasper (Quartz) (Silicon Dioxide (SiO2) with Iron impurities) — sedimentary

Red Jasper (Quartz)

Silicon Dioxide (SiO2) with Iron impurities

Shale or Argillite (Shale (sedimentary) / Argillite (metamorphic)) — Sedimentary or Metamorphic (low-grade)

Shale or Argillite

Shale (sedimentary) / Argillite (metamorphic)

Sedimentary or Metamorphic (low-grade)

Dyed Agate (Silicon Dioxide (SiO2) - variety Chalcedony) — mineral

Dyed Agate

Silicon Dioxide (SiO2) - variety Chalcedony

Turquoise (Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O) — mineral

Turquoise

Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O

Petrified Wood (Silicified Wood) (Silicified Wood / Silicon Dioxide (SiO2)) — metamorphic

Petrified Wood (Silicified Wood)

Silicified Wood / Silicon Dioxide (SiO2)

Carnelian (Carnelian (Microcrystalline Quartz, SiO2 with Fe2O3 impurities)) — mineral

Carnelian

Carnelian (Microcrystalline Quartz, SiO2 with Fe2O3 impurities)

Thunderegg (Agate-filled Rhyolitic Nodule (SiO2)) — mineral

Thunderegg

Agate-filled Rhyolitic Nodule (SiO2)

Blue Lace Agate (Tumbled) (Silicon Dioxide (SiO2)) — mineral

Blue Lace Agate (Tumbled)

Silicon Dioxide (SiO2)

Chert (often colloquially called Flint) (Chert (Microcrystalline Quartz, SiO2)) — sedimentary

Chert (often colloquially called Flint)

Chert (Microcrystalline Quartz, SiO2)

Chert (Jasper/Agate variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Jasper with Agate Inclusions (Jasper (Silicon Dioxide, SiO2) with Chalcedony/Agate) — sedimentary

Jasper with Agate Inclusions

Jasper (Silicon Dioxide, SiO2) with Chalcedony/Agate

Red Jasper (Silicon Dioxide with Iron Oxide impurities (SiO2 + Fe2O3)) — sedimentary

Red Jasper

Silicon Dioxide with Iron Oxide impurities (SiO2 + Fe2O3)

Chalcedony Nodule (Carnelian/Agate) (Chalcedony (Silicon Dioxide, SiO2)) — mineral

Chalcedony Nodule (Carnelian/Agate)

Chalcedony (Silicon Dioxide, SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified wood (Quartz, SiO2)) — metamorphic

Petrified Wood

Silicified wood (Quartz, SiO2)

Dyed Quartz (often sold as 'Blue Quartz' or 'Blue Agate') (Silicon Dioxide (SiO2) with artificial pigment) — mineral

Dyed Quartz (often sold as 'Blue Quartz' or 'Blue Agate')

Silicon Dioxide (SiO2) with artificial pigment

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

Jasper (Silicon dioxide (SiO2)) — sedimentary

Jasper

Silicon dioxide (SiO2)

Jasper and Ironstone (likely Jasperized Ironstone) (Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3)) — sedimentary

Jasper and Ironstone (likely Jasperized Ironstone)

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3)

Banded Agate (specifically Chalcedony nodule) (Agate (Silicon Dioxide, SiO2)) — mineral

Banded Agate (specifically Chalcedony nodule)

Agate (Silicon Dioxide, SiO2)

Blue Agate (Tumbled and Dyed) (Silicon Dioxide (SiO2) with likely organic dyes) — mineral

Blue Agate (Tumbled and Dyed)

Silicon Dioxide (SiO2) with likely organic dyes

Yellow Agate (Agate (Microcrystalline Silicon Dioxide, SiO2)) — mineral

Yellow Agate

Agate (Microcrystalline Silicon Dioxide, SiO2)