Rock Identifier

Category

Sedimentary (Cryptocrystalline Silica)

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

Chert (specifically Tan/Brown Chert) (Chert (SiO2)) — sedimentary

Chert (specifically Tan/Brown Chert)

Chert (SiO2)

Petrified Wood (Silicified wood (primarily Silicon Dioxide - SiO2)) — mineral (silicate-replaced organic material)

Petrified Wood

Silicified wood (primarily Silicon Dioxide - SiO2)

mineral (silicate-replaced organic material)

Petrified Wood (Silicified Wood (SiO2 - Quartz/Chalcendony replacing organic matter)) — sedimentary

Petrified Wood

Silicified Wood (SiO2 - Quartz/Chalcendony replacing organic matter)

Chert (Flint) (SiO2 (predominantly microcrystalline or cryptocrystalline quartz)) — Sedimentary rock

Chert (Flint)

SiO2 (predominantly microcrystalline or cryptocrystalline quartz)

Sedimentary rock

Chalcedony (Banded/Mottled Variety) (Chalcedony (a cryptocrystalline variety of Quartz, SiO2)) — Mineral

Chalcedony (Banded/Mottled Variety)

Chalcedony (a cryptocrystalline variety of Quartz, SiO2)

Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image) (SiO₂ (silicon dioxide)) — Sedimentary

Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image)

SiO₂ (silicon dioxide)

Jasper (Imperial Jasper style) (Silicon Dioxide (SiO2) with impurities) — sedimentary

Jasper (Imperial Jasper style)

Silicon Dioxide (SiO2) with impurities

Carnelian (Carnelian (a variety of Chalcedony, SiO2)) — Mineral

Carnelian

Carnelian (a variety of Chalcedony, SiO2)

Agate Geode Slice (with Druzy Quartz) (Silicon Dioxide (SiO2)) — mineral

Agate Geode Slice (with Druzy Quartz)

Silicon Dioxide (SiO2)

Carnelian (Chalcedony (cryptocrystalline quartz), SiO2 (Silicon Dioxide)) — Mineral

Carnelian

Chalcedony (cryptocrystalline quartz), SiO2 (Silicon Dioxide)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Banded Jasper (Silicon Dioxide (SiO2)) — Mineral/Sedimentary Rock (as a cryptocrystalline variety of quartz)

Banded Jasper

Silicon Dioxide (SiO2)

Mineral/Sedimentary Rock (as a cryptocrystalline variety of quartz)

Limonite (Ironstone Concretion) (Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)) — mineral

Limonite (Ironstone Concretion)

Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)

Petrified Wood (Silicified Wood (primarily SiO₂ - Silicon Dioxide)) — metamorphic

Petrified Wood

Silicified Wood (primarily SiO₂ - Silicon Dioxide)

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

Banded Agate

Cryptocrystalline Silicon Dioxide (SiO2)

Chalcedony (or a variety of Chalcedony, likely Agate or Jasper) (Chalcedony (SiO₂)) — Mineral (or mineraloid if microcrystalline)

Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)

Chalcedony (SiO₂)

Mineral (or mineraloid if microcrystalline)

Jasper (Silicon dioxide (SiO2)) — Mineral

Jasper

Silicon dioxide (SiO2)

Blue Chalcedony (Chalcedony (a cryptocrystalline variety of Quartz - SiO₂)) — Mineral

Blue Chalcedony

Chalcedony (a cryptocrystalline variety of Quartz - SiO₂)

Petrified Wood (Silicified Wood (primarily SiO2)) — metamorphic

Petrified Wood

Silicified Wood (primarily SiO2)

Jasper River Pebble (Jasper (Silicon Dioxide, SiO2)) — sedimentary (cryptocrystalline quartz)

Jasper River Pebble

Jasper (Silicon Dioxide, SiO2)

sedimentary (cryptocrystalline quartz)

Flint (Chert (a form of cryptocrystalline quartz, chemical formula SiO₂)) — Mineral

Flint

Chert (a form of cryptocrystalline quartz, chemical formula SiO₂)

Jasper River Pebble (Silicon Dioxide (SiO2)) — sedimentary (microcrystalline quartz)

Jasper River Pebble

Silicon Dioxide (SiO2)

sedimentary (microcrystalline quartz)

Cherry Creek Jasper (also known as Red Creek Jasper or Cherry Creek Agate) (Jasper, microcrystalline quartz (SiO₂)) — Sedimentary Rock

Cherry Creek Jasper (also known as Red Creek Jasper or Cherry Creek Agate)

Jasper, microcrystalline quartz (SiO₂)

Sedimentary Rock

Carnelian (Orange Agate) (Silicon Dioxide (SiO2)) — mineral

Carnelian (Orange Agate)

Silicon Dioxide (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Agate (Agate (a cryptocrystalline variety of Quartz, SiO₂)) — Mineral

Agate

Agate (a cryptocrystalline variety of Quartz, SiO₂)

Chert / Flint (a variety of Chert) (Chert (SiO2)) — Sedimentary Rock (technically a microcrystalline quartz mineral aggregate)

Chert / Flint (a variety of Chert)

Chert (SiO2)

Sedimentary Rock (technically a microcrystalline quartz mineral aggregate)

Mookaite Jasper (Siliceous (chert) sedimentary rock, a form of Jasper) — Sedimentary

Mookaite Jasper

Siliceous (chert) sedimentary rock, a form of Jasper

Banded Chert (Cryptocrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Cryptocrystalline Quartz (SiO2)

Carnelian (Chalcedony (cryptocrystalline quartz), SiO2) — Mineral

Carnelian

Chalcedony (cryptocrystalline quartz), SiO2

Chert (Gravel) (Chert (Cryptocrystalline silicon dioxide, SiO2)) — sedimentary

Chert (Gravel)

Chert (Cryptocrystalline silicon dioxide, SiO2)

Agate (Dyed High-Grade Polished Slice) (Silicon dioxide (SiO2), Chalcedony crystal variety) — mineral

Agate (Dyed High-Grade Polished Slice)

Silicon dioxide (SiO2), Chalcedony crystal variety

Chert / Flint (Chert (varieties include Flint)) — Sedimentary

Chert / Flint

Chert (varieties include Flint)

Petrified Wood (Silicified Wood (primarily SiO₂ - Silicon Dioxide)) — metamorphic

Petrified Wood

Silicified Wood (primarily SiO₂ - Silicon Dioxide)

Dyed Agate (Silicon Dioxide (SiO2) with synthetic dyes) — mineral

Dyed Agate

Silicon Dioxide (SiO2) with synthetic dyes

Banded Agate (Agate (Cryptocrystalline variety of Silica, SiO2)) — mineral

Banded Agate

Agate (Cryptocrystalline variety of Silica, SiO2)

Pebble (likely Quartz or Chert) (SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.) — Sedimentary Rock

Pebble (likely Quartz or Chert)

SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.

Sedimentary Rock

Chalcedony (Botryoidal or Agate nodule) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Botryoidal or Agate nodule)

Silicon Dioxide (SiO2)

Quartz (likely Jasper or Chert variety) (Quartz (SiO₂)) — Mineral

Quartz (likely Jasper or Chert variety)

Quartz (SiO₂)

Limonite (Ironstone) (Hydrated Iron Oxide (FeO(OH)·nH2O)) — mineral

Limonite (Ironstone)

Hydrated Iron Oxide (FeO(OH)·nH2O)

Quartz Pebble (Silicon Dioxide (SiO2)) — Mineral / Sedimentary component

Quartz Pebble

Silicon Dioxide (SiO2)

Mineral / Sedimentary component

Banded Agate (Cryptocrystalline Quartz (SiO2)) — mineral

Banded Agate

Cryptocrystalline Quartz (SiO2)