Rock Identifier

Category

Sedimentary (Formed From Silica Deposits)

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

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

Amethyst

Silicon dioxide with iron impurities (SiO2)

Grey River Pebble (Likely Quartz-rich or Limestone) (Clastic Sedimentary Rock (typically SiO2 or CaCO3 based)) — sedimentary

Grey River Pebble (Likely Quartz-rich or Limestone)

Clastic Sedimentary Rock (typically SiO2 or CaCO3 based)

Puddingstone (Conglomerate (Indurated)) — sedimentary

Puddingstone

Conglomerate (Indurated)

Chert (Jasper/Flint variety) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (Jasper/Flint variety)

Microcrystalline quartz (SiO2)

Chert (specifically as a lithic artifact/projectile point) (Chert (Silicon dioxide, SiO2)) — sedimentary

Chert (specifically as a lithic artifact/projectile point)

Chert (Silicon dioxide, SiO2)

River Siltstone / Mudstone Pebble (Siltstone (composed of mixed silicate and carbonate minerals)) — sedimentary

River Siltstone / Mudstone Pebble

Siltstone (composed of mixed silicate and carbonate minerals)

Quartz Geode (Citrine or Iron-stained Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz Geode (Citrine or Iron-stained Quartz)

Silicon Dioxide (SiO2)

Septarian Nodule (Septarian concretion (Complex mixture of Siderite, Calcite, and Aragonite)) — sedimentary

Septarian Nodule

Septarian concretion (Complex mixture of Siderite, Calcite, and Aragonite)

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

Hematite

Iron(III) oxide (Fe2O3)

Mixed Tumbled Stones (Mostly Agate, Jasper, and Quartz) (Silicon Dioxide (SiO2)) — sedimentary and metamorphic minerals

Mixed Tumbled Stones (Mostly Agate, Jasper, and Quartz)

Silicon Dioxide (SiO2)

sedimentary and metamorphic minerals

Milky Quartz (Silicon dioxide (SiO2)) — mineral

Milky Quartz

Silicon dioxide (SiO2)

Agate (various color varieties) (SiO₂ (Silicon Dioxide)) — Mineral (specifically a variety of Chalcedony, which is a microcrystalline quartz)

Agate (various color varieties)

SiO₂ (Silicon Dioxide)

Mineral (specifically a variety of Chalcedony, which is a microcrystalline quartz)

Quartzite Pebble (Metamorphosed Quartz Sandstone (SiO2)) — metamorphic

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Magnetite / Iron Ore (Magnetite (Fe3O4)) — mineral

Magnetite / Iron Ore

Magnetite (Fe3O4)

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

Amethyst

Silicon Dioxide (SiO2) containing Iron impurities

Sandstone (Quartzose Sandstone) (Arenite (SiO2 principal component)) — sedimentary

Sandstone (Quartzose Sandstone)

Arenite (SiO2 principal component)

Riverstone (Quartzite or Siltstone cobble) (Quartzite (primarily SiO2)) — metamorphic

Riverstone (Quartzite or Siltstone cobble)

Quartzite (primarily SiO2)

Sandstone with Manganese Dendrites/Oxide coatings (Arenite with Pyrolusite and Romanechite (MnO2)) — sedimentary

Sandstone with Manganese Dendrites/Oxide coatings

Arenite with Pyrolusite and Romanechite (MnO2)

Crushed Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Crushed Limestone

Calcium Carbonate (CaCO3)

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

Amethyst (Geode)

Silicon Dioxide (SiO2) with iron impurities

Clear Quartz (Silicon Dioxide (SiO2)) — mineral

Clear Quartz

Silicon Dioxide (SiO2)

Blue Lace Agate (Chalcedony (SiO2) with trace minerals) — mineral

Blue Lace Agate

Chalcedony (SiO2) with trace minerals

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

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Sodalite (Sodalite - Na8(Al6Si6O24)Cl2) — mineral

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

Bull Quartz (White Quartz) (Silicon Dioxide (SiO2)) — mineral

Bull Quartz (White Quartz)

Silicon Dioxide (SiO2)

Limonite (Iron Stone Concretion) (Limonite (Hydrous Iron Oxide) - FeO(OH)·nH2O) — mineral

Limonite (Iron Stone Concretion)

Limonite (Hydrous Iron Oxide) - FeO(OH)·nH2O

Sandstone (likely Quartz Sandstone) (Arenite (SiO2 based)) — sedimentary

Sandstone (likely Quartz Sandstone)

Arenite (SiO2 based)

Quartz (Iron-stained) (Silicon Dioxide (SiO2)) — mineral

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Ocean Jasper (Silicon Dioxide (SiO2)) — Mineral_variety_of_Chalcedony

Ocean Jasper

Silicon Dioxide (SiO2)

Mineral_variety_of_Chalcedony

Quartz Pebble (Chalcedony/Agate) (Silicon Dioxide (SiO2)) — Mineral

Quartz Pebble (Chalcedony/Agate)

Silicon Dioxide (SiO2)

Septarian Nodule (Septarian Concretion (CaCO3 with Siderite and Calcite/Aragonite infusions)) — sedimentary

Septarian Nodule

Septarian Concretion (CaCO3 with Siderite and Calcite/Aragonite infusions)

Chalk (Calcareous Ooze (composed primarily of coccoliths)) — Sedimentary Rock

Chalk

Calcareous Ooze (composed primarily of coccoliths)

Sedimentary Rock

Hematite (Iron(III) oxide (Fe2O3)) — Mineral

Hematite

Iron(III) oxide (Fe2O3)

Orange Calcite (Cleavage Rhomb) (Calcite (Calcium Carbonate, CaCO3)) — mineral

Orange Calcite (Cleavage Rhomb)

Calcite (Calcium Carbonate, CaCO3)

Chalcedony (Quartz Nodule) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Quartz Nodule)

Silicon Dioxide (SiO2)

Blue Chalcedony (Silicon Dioxide (SiO2)) — mineral

Blue Chalcedony

Silicon Dioxide (SiO2)

Red Sandstone (Clastic Sedimentary Mineraloid (predominantly Quartz grains with Iron Oxide cement)) — sedimentary

Red Sandstone

Clastic Sedimentary Mineraloid (predominantly Quartz grains with Iron Oxide cement)

Quartz (Crystal/Druzy Quartz) (Quartz (SiO₂)) — Mineral

Quartz (Crystal/Druzy Quartz)

Quartz (SiO₂)

Carnelian Agate (Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3) inclusions) — mineral

Carnelian Agate

Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3) inclusions

Granite (Phaneritic Igneous Rock (composed mostly of Quartz, Feldspar, and Mica)) — igneous

Granite

Phaneritic Igneous Rock (composed mostly of Quartz, Feldspar, and Mica)

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

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Amygdaloidal Rhyolite (Amygdaloidal felsic extrusive rock) — igneous

Amygdaloidal Rhyolite

Amygdaloidal felsic extrusive rock