Rock Identifier

Category

Sedimentary (Formed From Silica Deposits)

Browse sedimentary (formed from silica deposits) specimens identified by the Rock Identifier community.

Apache Tear (Obsidian (Hydrated Volcanic Glass, SiO2)) — igneous

Apache Tear

Obsidian (Hydrated Volcanic Glass, SiO2)

Magnetite (Iron(II,III) oxide (Fe3O4)) — mineral

Magnetite

Iron(II,III) oxide (Fe3O4)

Amethyst (Amethyst (Silicon Dioxide, SiO2 with Iron impurities)) — mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2 with Iron impurities)

Halite (Halite (NaCl)) — Mineral

Halite

Halite (NaCl)

Chert (often called Flint when dark) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Coquina (Biogenic Limestone (Coquina)) — sedimentary

Coquina

Biogenic Limestone (Coquina)

Ammonite Fossil (Ammonoidea (Calcium carbonate - CaCO3)) — sedimentary

Ammonite Fossil

Ammonoidea (Calcium carbonate - CaCO3)

Botryoidal Chalcedony (Agate/Chert Nodule) (Chalcedony (SiO2)) — mineral

Botryoidal Chalcedony (Agate/Chert Nodule)

Chalcedony (SiO2)

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

Chalcedony (Agate)

Silicon Dioxide (SiO2)

Travertine (Tufa) (Calcium Carbonate (CaCO3)) — sedimentary

Travertine (Tufa)

Calcium Carbonate (CaCO3)

Quartz Pebble (Silicon Dioxide (SiO2)) — Mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz (Water-worn Pebble) (Silicon Dioxide (SiO2)) — mineral

Quartz (Water-worn Pebble)

Silicon Dioxide (SiO2)

Milky Quartz with Iron Staining (Silicon Dioxide (SiO2)) — mineral

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

Granite Cobble (Phaneritic Felsic Igneous Rock) — igneous

Granite Cobble

Phaneritic Felsic Igneous Rock

Carnelian Agate (with Quartz/Chalcedony) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — mineral

Carnelian Agate (with Quartz/Chalcedony)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

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

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Limonite with Hematite (Limonite (FeO(OH)·nH2O) and Hematite (Fe2O3)) — mineral

Limonite with Hematite

Limonite (FeO(OH)·nH2O) and Hematite (Fe2O3)

Specular Hematite (Iron Ore) (Iron(III) oxide (Fe2O3)) — mineral

Specular Hematite (Iron Ore)

Iron(III) oxide (Fe2O3)

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

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)

Indian Agate (Cryptocrystalline Quartz (SiO2)) — mineral

Indian Agate

Cryptocrystalline Quartz (SiO2)

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

Dyed Agate Slice

Silicon Dioxide (SiO2) - variety of Chalcedony

Auriferous Quartz (Gold-bearing Quartz) (Silicon Dioxide (SiO2) with Elemental Gold (Au)) — mineral

Auriferous Quartz (Gold-bearing Quartz)

Silicon Dioxide (SiO2) with Elemental Gold (Au)

Amethyst (Silicon Dioxide (SiO2) with Fe3+ impurities) — mineral

Amethyst

Silicon Dioxide (SiO2) with Fe3+ impurities

Fluorite Octahedron (Fluorite (Calcium Fluoride, CaF2)) — mineral

Fluorite Octahedron

Fluorite (Calcium Fluoride, CaF2)

Quartz (Milky or Iron-Stained) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky or Iron-Stained)

Silicon Dioxide (SiO2)

Greenstone with Quartz Veining (Epidiorite or Metabasalt with SiO2 (Quartz) veins) — metamorphic

Greenstone with Quartz Veining

Epidiorite or Metabasalt with SiO2 (Quartz) veins

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Banded Rhyolite (likely Green Jasper/Agate variety) (Silicon Dioxide (SiO2) with mineral inclusions) — igneous

Banded Rhyolite (likely Green Jasper/Agate variety)

Silicon Dioxide (SiO2) with mineral inclusions

Quartzite River Pebbles (Quartzite (primarily SiO2)) — Metamorphic

Quartzite River Pebbles

Quartzite (primarily SiO2)

Sandstone Concretion (Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)) — sedimentary

Sandstone Concretion

Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)

Clear Quartz (Rock Crystal) (Silicon Dioxide (SiO2)) — mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz Cluster (Quartz (Silicon Dioxide - SiO2)) — mineral

Clear Quartz Cluster

Quartz (Silicon Dioxide - SiO2)

Milky Quartz (Quartz (Silicon Dioxide, SiO2)) — mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

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

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

White Quartz Pebble (with possible Quartz Geode cavity) (Silicon Dioxide (SiO2)) — mineral

White Quartz Pebble (with possible Quartz Geode cavity)

Silicon Dioxide (SiO2)

Crinoid Stem Fossil (Class Crinoidea (Phylum Echinodermata), often preserved in Limestone or Calcite (CaCO3)) — sedimentary

Crinoid Stem Fossil

Class Crinoidea (Phylum Echinodermata), often preserved in Limestone or Calcite (CaCO3)

Amethyst (SiO2 (Silicon Dioxide) - Purple variety of Quartz) — mineral

Amethyst

SiO2 (Silicon Dioxide) - Purple variety of Quartz

Apache Tear (Hydrated Obsidians (Volcanic Glass)) — igneous

Apache Tear

Hydrated Obsidians (Volcanic Glass)

Carnelian Agate (Silicon dioxide (SiO2) - variety of chalcedony) — mineral

Carnelian Agate

Silicon dioxide (SiO2) - variety of chalcedony

Quartzite (Quartzite (composed primarily of SiO2)) — metamorphic

Quartzite

Quartzite (composed primarily of SiO2)

Sodalite Syenite (Sodalite-bearing Syenite (Na8(Al6Si6O24)Cl2)) — igneous

Sodalite Syenite

Sodalite-bearing Syenite (Na8(Al6Si6O24)Cl2)