Rock Identifier

Category

Sedimentary (Formed From Silica Deposits)

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

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Hematite (Ferric oxide (Fe2O3)) — mineral

Hematite

Ferric oxide (Fe2O3)

Quartz (pebble) (Quartz (SiO₂)) — Mineral

Quartz (pebble)

Quartz (SiO₂)

Chert (specifically Banded Chert) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Banded Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chalk (Calcium Carbonate (CaCO3)) — sedimentary

Chalk

Calcium Carbonate (CaCO3)

Ferruginous Quartz (River Pebble) (Silicon Dioxide (SiO2) with Iron Oxide inclusions) — mineral

Ferruginous Quartz (River Pebble)

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Granite (Granite) — igneous

Granite

Granite

Carnelian (Carnelian (a variety of Chalcedony, which is a microcrystalline quartz, SiO2)) — Mineral (variety of Chalcedony)

Carnelian

Carnelian (a variety of Chalcedony, which is a microcrystalline quartz, SiO2)

Mineral (variety of Chalcedony)

Banded Sandstone (Arenite (with iron oxide banding)) — sedimentary

Banded Sandstone

Arenite (with iron oxide banding)

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

Agate

Agate (a variety of Chalcedony, SiO2)

Amethyst (SiO2 (Silicon Dioxide with iron impurities)) — mineral

Amethyst

SiO2 (Silicon Dioxide with iron impurities)

Selenite (Satin Spar) (Gypsum (CaSO4·2H2O)) — mineral

Selenite (Satin Spar)

Gypsum (CaSO4·2H2O)

River Cobble (Quartzite-rich Sandstone) (Clastic Sedimentary Rock (Litharenite/Quartzite transition)) — sedimentary

River Cobble (Quartzite-rich Sandstone)

Clastic Sedimentary Rock (Litharenite/Quartzite transition)

Sandstone (Greywacke/Siltstone variant) (Clastic Sedimentary Rock (composed primarily of Quartz SiO2 and Feldspar)) — sedimentary

Sandstone (Greywacke/Siltstone variant)

Clastic Sedimentary Rock (composed primarily of Quartz SiO2 and Feldspar)

Coquina (Fossiliferous Limestone) (Biogenic Limestone (Calcium Carbonate, CaCO3)) — sedimentary

Coquina (Fossiliferous Limestone)

Biogenic Limestone (Calcium Carbonate, CaCO3)

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

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

Cloudy Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

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

Banded Agate (Botswana Agate)

Silicon Dioxide (SiO2)

Granite (Felsic Intrusive Igneous Rock) — igneous

Granite

Felsic Intrusive Igneous Rock

Quartz Vein in Metamorphic Rock (Silicon Dioxide (SiO2) within Metasedimentary host) — metamorphic

Quartz Vein in Metamorphic Rock

Silicon Dioxide (SiO2) within Metasedimentary host

Hematite (Hematite (Iron(III) oxide, Fe2O3)) — mineral

Hematite

Hematite (Iron(III) oxide, Fe2O3)

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

Amethyst

Silicon Dioxide with Iron impurities (SiO2)

Hematite (Tumbled) (Iron(III) oxide (Fe2O3)) — mineral

Hematite (Tumbled)

Iron(III) oxide (Fe2O3)

Amethyst Quartz Pebble (Silicon Dioxide (SiO2) with iron impurities) — mineral

Amethyst Quartz Pebble

Silicon Dioxide (SiO2) with iron impurities

River Rocks (Basalt and Sedimentary Stones) (Mafic Igneous Rock (Basalt) and Clastic Sedimentary Rock) — igneous and sedimentary

River Rocks (Basalt and Sedimentary Stones)

Mafic Igneous Rock (Basalt) and Clastic Sedimentary Rock

igneous and sedimentary

Pink Calcite (Mangano Calcite) (Calcium Carbonate (CaCO3)) — mineral

Pink Calcite (Mangano Calcite)

Calcium Carbonate (CaCO3)

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

Limonite (with Goethite/Ironstone)

FeO(OH)·nH2O (Hydrated Iron Oxide)

Amethyst (Amethyst (Silicon Dioxide, SiO2)) — mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Blue Calcite (Calcium Carbonate (CaCO3)) — mineral

Blue Calcite

Calcium Carbonate (CaCO3)

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

Obsidian (Apache Tear)

Volcanic Glass (SiO2)

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

Turquoise

CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminum phosphate)

Septarian Nodule (Septaria) (Septarian Nodule (Calcium Carbonate/Aragonite/Calcite Concretion)) — sedimentary

Septarian Nodule (Septaria)

Septarian Nodule (Calcium Carbonate/Aragonite/Calcite Concretion)

Blue Calcite (Calcite (CaCO3)) — mineral

Blue Calcite

Calcite (CaCO3)

Sandstone (Quartzose) (Arenite (primarily SiO2)) — sedimentary

Sandstone (Quartzose)

Arenite (primarily SiO2)

Siltstone (Siltstone (composed of clastic quartz and feldspar)) — sedimentary

Siltstone

Siltstone (composed of clastic quartz and feldspar)

Coquina / Shelly Limestone (Bioclastic Limestone (composed of CaCO3)) — sedimentary

Coquina / Shelly Limestone

Bioclastic Limestone (composed of CaCO3)

Epidote with Magnetite/Hematite inclusions (Epidote (Ca2(Al2,Fe3+)(SiO4)3(OH)) with Iron Oxides) — mineral

Epidote with Magnetite/Hematite inclusions

Epidote (Ca2(Al2,Fe3+)(SiO4)3(OH)) with Iron Oxides

Amethyst (Amethyst (Silicon Dioxide, SiO2)) — mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Ferruginous Quartz (Silicon Dioxide (SiO2) with Iron Oxide inclusions (Hematite/Limonite)) — mineral

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide inclusions (Hematite/Limonite)

Limonite (Iron Ore) (Limonite (FeO(OH)·nH2O)) — mineral

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Flesh-toned Siltstone (Siltstone (composed of microscopic Quartz and Feldspar grains)) — sedimentary

Flesh-toned Siltstone

Siltstone (composed of microscopic Quartz and Feldspar grains)