Rock Identifier

Category

Mineral Precipitate (Anthropogenic Context)

Browse mineral precipitate (anthropogenic context) specimens identified by the Rock Identifier community.

Quartz Pebble (Geode-like) (Silicon Dioxide (SiO2)) — Mineral

Quartz Pebble (Geode-like)

Silicon Dioxide (SiO2)

Pink Opal (Common Opal) (Amorphous Hydrated Silica (SiO2·nH2O)) — mineral

Pink Opal (Common Opal)

Amorphous Hydrated Silica (SiO2·nH2O)

Jasper (Jasper (Cryptocrystalline variety of Quartz, SiO2)) — sedimentary

Jasper

Jasper (Cryptocrystalline variety of Quartz, SiO2)

Blue Goldstone (Goldstone (artificial glass)) — Mineral (man-made glass, not natural)

Blue Goldstone

Goldstone (artificial glass)

Mineral (man-made glass, not natural)

Petrified Wood (Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)) — Mineral/Fossil (Sedimentary context)

Petrified Wood

Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)

Mineral/Fossil (Sedimentary context)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Common Opal (Hydrated silica (SiO2 " nH2O)) — mineral

Common Opal

Hydrated silica (SiO2 " nH2O)

Quartz Geode (with Agate banding) (Silicon Dioxide (SiO2)) — Sedimentary or Igneous (secondary formation)

Quartz Geode (with Agate banding)

Silicon Dioxide (SiO2)

Sedimentary or Igneous (secondary formation)

Jasper Geode (Silicon Dioxide (SiO2) with impurities) — sedimentary

Jasper Geode

Silicon Dioxide (SiO2) with impurities

Quartz (Quartz (SiO₂)) — Mineral

Quartz

Quartz (SiO₂)

Pyrite (Fool's Gold) (Iron Disulfide (FeS2)) — mineral

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Sandstone with Liesegang Rings (Arenite with Iron Oxide Liesegang Banding) — sedimentary

Sandstone with Liesegang Rings

Arenite with Iron Oxide Liesegang Banding

Quartzite with vugs/druzy quartz (Crystalline Silicon Dioxide (SiO2)) — metamorphic

Quartzite with vugs/druzy quartz

Crystalline Silicon Dioxide (SiO2)

Banded Iron Formation (BIF) (Banded Iron Formation (Magnetite-Hematite-Chert)) — sedimentary

Banded Iron Formation (BIF)

Banded Iron Formation (Magnetite-Hematite-Chert)

Jasper (Silicon dioxide (SiO2)) — sedimentary

Jasper

Silicon dioxide (SiO2)

Septarian Nodule (Galt) (Calcareous concretion / Septarian concretion) — sedimentary

Septarian Nodule (Galt)

Calcareous concretion / Septarian concretion

Jasper with Quartz Druzy (Silicon Dioxide (SiO2)) — sedimentary

Jasper with Quartz Druzy

Silicon Dioxide (SiO2)

Ferruginous Sandstone (Grit) (Clastic Sedimentary (Ironstone-rich Sandstone)) — sedimentary

Ferruginous Sandstone (Grit)

Clastic Sedimentary (Ironstone-rich Sandstone)

Iron Ore (Hematite/Magnetite mixture) (Ferrous Oxide (Fe2O3 / Fe3O4)) — sedimentary

Iron Ore (Hematite/Magnetite mixture)

Ferrous Oxide (Fe2O3 / Fe3O4)

Aragonite Star Cluster (Aragonite (Calcium Carbonate, CaCO3)) — mineral

Aragonite Star Cluster

Aragonite (Calcium Carbonate, CaCO3)

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

Thunderegg

Agate-filled Rhyolitic Nodule (SiO2)

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

Quartz Vein / Milky Quartz

Silicon Dioxide (SiO2)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Bloodstone (Heliotrope) (Silicon Dioxide (SiO2) - Variety of Chalcedony/Jasper) — mineral

Bloodstone (Heliotrope)

Silicon Dioxide (SiO2) - Variety of Chalcedony/Jasper

Carnelian (Carnelian Chalcedony (SiO2)) — mineral

Carnelian

Carnelian Chalcedony (SiO2)

Jasper (Iron-stained Chert) (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Jasper (Iron-stained Chert)

Silicon Dioxide (SiO2) with iron oxide inclusions

Clear Quartz (or Rock Crystal) (Quartz (SiO₂)) — Mineral

Clear Quartz (or Rock Crystal)

Quartz (SiO₂)

Agate (specifically Carnelian Agate or Lake Superior style Agate) (Silicon Dioxide (SiO2) - Cryptocrystalline Quartz) — mineral

Agate (specifically Carnelian Agate or Lake Superior style Agate)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Dyed Quartz Geode (Silicon Dioxide (SiO2) with artificial pigment) — mineral

Dyed Quartz Geode

Silicon Dioxide (SiO2) with artificial pigment

Quartz Geode Fragment (Silicon Dioxide (SiO2)) — mineral

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Quartz Geode (Silicon Dioxide (SiO₂)) — mineral

Quartz Geode

Silicon Dioxide (SiO₂)

Amygdaloidal Basalt (Amygdaloidal Basalt (Host rock) with Quartz or Calcite amygdules) — igneous

Amygdaloidal Basalt

Amygdaloidal Basalt (Host rock) with Quartz or Calcite amygdules

Dolomite (Dolomite (CaMg(CO3)2)) — Mineral

Dolomite

Dolomite (CaMg(CO3)2)

Agate (translucent pebble) (Silicon dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Agate (translucent pebble)

Silicon dioxide (SiO2) - Microcrystalline Quartz

Chalcedony (variations like Agate or Jasper) (Chalcedony (SiO₂ - microcrystalline quartz)) — Mineral

Chalcedony (variations like Agate or Jasper)

Chalcedony (SiO₂ - microcrystalline quartz)

Amethyst Geode (Silicon Dioxide with trace inclusions of Iron (SiO2)) — mineral

Amethyst Geode

Silicon Dioxide with trace inclusions of Iron (SiO2)

Blue Agate (likely dyed) (Silicon Dioxide (SiO2)) — mineral

Blue Agate (likely dyed)

Silicon Dioxide (SiO2)

Banded Agate (specifically Eye Agate / Chalcedony) (Agate (Cryptocrystalline variety of Quartz, SiO2)) — mineral

Banded Agate (specifically Eye Agate / Chalcedony)

Agate (Cryptocrystalline variety of Quartz, SiO2)

Chalcedony (Common Opal/Chert variety) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Common Opal/Chert variety)

Silicon Dioxide (SiO2)

Honey Calcite (Calcium Carbonate (CaCO3)) — mineral

Honey Calcite

Calcium Carbonate (CaCO3)