Rock Identifier

Category

Sedimentary Or Igneous (Secondary Formation)

Browse sedimentary or igneous (secondary formation) specimens identified by the Rock Identifier community.

Learn about Sedimentary Or Igneous (Secondary Formation) in the encyclopedia

Banded Iron Formation

Banded Iron Formation

Itabirite

Jaspillite

Carbonatite

Conglomerate

Quartzite Sandstone

Quartzite Sandstone

Breccia

Ironstone

Lamproite

Troctolite

Basalt

Gabbro

Citrine Quartz Geode (Silicon Dioxide (SiO2) with iron impurities) — mineral

Citrine Quartz Geode

Silicon Dioxide (SiO2) with iron impurities

Kaolinite (Chalky Clay) (Kaolinite (Al2Si2O5(OH)4)) — sedimentary

Kaolinite (Chalky Clay)

Kaolinite (Al2Si2O5(OH)4)

Limonite (Iron Ore/Hydrated Iron Oxide) (Limonite (mixture of FeO(OH)·nH₂O minerals, mainly Goethite, FeO(OH) and Lepidocrocite, FeO(OH))) — Mineral

Limonite (Iron Ore/Hydrated Iron Oxide)

Limonite (mixture of FeO(OH)·nH₂O minerals, mainly Goethite, FeO(OH) and Lepidocrocite, FeO(OH))

Rhodochrosite (Manganese Carbonate (MnCO3)) — mineral

Rhodochrosite

Manganese Carbonate (MnCO3)

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

Quartz (Druzy)

Silicon Dioxide (SiO2)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

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

Yellow Chalcedony (Agate Pebble)

Silicon Dioxide (SiO2)

Banded Gneiss (Gneiss) — metamorphic

Banded Gneiss

Gneiss

Magnetite (Lodestone variety) (Magnetite (Fe3O4)) — mineral

Magnetite (Lodestone variety)

Magnetite (Fe3O4)

Blue Apatite (Apatite - Ca5(PO4)3(F,Cl,OH)) — mineral

Blue Apatite

Apatite - Ca5(PO4)3(F,Cl,OH)

Chalcedony (Grey/White Agate) (Silicon Dioxide (SiO₂)) — mineral

Chalcedony (Grey/White Agate)

Silicon Dioxide (SiO₂)

Weathered brown stone, possibly basalt or iron-rich sedimentary rock (Indeterminate from photograph; likely fine-grained mafic rock (basalt) or ferruginous sandstone) — igneous

Weathered brown stone, possibly basalt or iron-rich sedimentary rock

Indeterminate from photograph; likely fine-grained mafic rock (basalt) or ferruginous sandstone

Magnetite (Magnetite (Fe3O4)) — mineral

Magnetite

Magnetite (Fe3O4)

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

Magnetite / Iron Ore

Magnetite (Fe3O4)

Prehnite (Prehnite (Ca2Al2Si3O10(OH)2)) — mineral

Prehnite

Prehnite (Ca2Al2Si3O10(OH)2)

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

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Red Jasper (Silicon Dioxide (SiO2) with Iron inclusions) — sedimentary

Red Jasper

Silicon Dioxide (SiO2) with Iron inclusions

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Seashell (Calcium Carbonate) (Calcium Carbonate (CaCO3)) — mineral

Seashell (Calcium Carbonate)

Calcium Carbonate (CaCO3)

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

Chalcedony (Agate)

Silicon Dioxide (SiO2)

Fluorite Tower (Fluorite (Calcium Fluoride - CaF2)) — mineral

Fluorite Tower

Fluorite (Calcium Fluoride - CaF2)

Quartz Geode (Silicon Dioxide (SiO2)) — mineral

Quartz Geode

Silicon Dioxide (SiO2)

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

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Calcite (Calcium Carbonate (CaCO3)) — mineral

Calcite

Calcium Carbonate (CaCO3)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Chert (Jasper / Flint variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper / Flint variant)

Microcrystalline Quartz (SiO2)

Banded Agate (Cryptocrystalline Quartz (SiO2)) — sedimentary

Banded Agate

Cryptocrystalline Quartz (SiO2)

Banded Calcite (often sold as Mexican Onyx) (Calcium Carbonate (CaCO3)) — mineral

Banded Calcite (often sold as Mexican Onyx)

Calcium Carbonate (CaCO3)

Diamond Druzy (Crystalline Diamond) (Carbon (C)) — mineral

Diamond Druzy (Crystalline Diamond)

Carbon (C)

Gold Nugget (Native Gold (Au)) — mineral

Gold Nugget

Native Gold (Au)

Iron-stained Quartz (Silicon Dioxide (SiO2) with Hematite/Limonite impurities) — mineral

Iron-stained Quartz

Silicon Dioxide (SiO2) with Hematite/Limonite impurities

Quartz Pebble (Silicon Dioxide (SiO2)) — sedimentary

Quartz Pebble

Silicon Dioxide (SiO2)

Chert on Volcanic Host Rock (Sedimentary Chert (SiO2) within Basalt or Andesite) — sedimentary

Chert on Volcanic Host Rock

Sedimentary Chert (SiO2) within Basalt or Andesite

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

Magnetite (Iron Ore)

Magnetite (Fe3O4)

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

Magnetite (Iron Ore)

Magnetite (Fe3O4)

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Pyrite (Iron Pyrite (FeS2)) — mineral

Pyrite

Iron Pyrite (FeS2)

Quartz (Silicon dioxide (SiO2)) — Mineral

Quartz

Silicon dioxide (SiO2)

Malachite (Cu2CO3(OH)2 (Copper carbonate hydroxide)) — mineral

Malachite

Cu2CO3(OH)2 (Copper carbonate hydroxide)

Pyritic Gneiss (with Garnet) (Gneiss containing Pyrite (FeS2) and Almandine Garnet (Fe3Al2(SiO4)3)) — metamorphic

Pyritic Gneiss (with Garnet)

Gneiss containing Pyrite (FeS2) and Almandine Garnet (Fe3Al2(SiO4)3)

Basalt (Mafic Igneous Rock (composed primarily of pyroxene and calcium-rich plagioclase)) — igneous

Basalt

Mafic Igneous Rock (composed primarily of pyroxene and calcium-rich plagioclase)

Iron-stained Quartz (Silicon Dioxide (SiO2) with Hematite/Limonite inclusions) — mineral

Iron-stained Quartz

Silicon Dioxide (SiO2) with Hematite/Limonite inclusions