Rock Identifier

Category

Sedimentary Or Igneous (Secondary Formation)

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

River Stone (Basalt or Siltstone with banding) (Polished Basaltic or Siliciclastic River Cobble) — igneous or sedimentary

River Stone (Basalt or Siltstone with banding)

Polished Basaltic or Siliciclastic River Cobble

igneous or sedimentary

Sodalite (Sodalite (Na4Al3Si3O12Cl)) — Mineral

Sodalite

Sodalite (Na4Al3Si3O12Cl)

Moonstone (Adularia (orthoclase feldspar variety)) — mineral

Moonstone

Adularia (orthoclase feldspar variety)

Hematite (Hematite (Fe2O3)) — mineral

Hematite

Hematite (Fe2O3)

Calcite (Calcite (CaCO3)) — Mineral

Calcite

Calcite (CaCO3)

Black Kyanite (Kyanite (Al2SiO5) with carbonaceous inclusions) — mineral

Black Kyanite

Kyanite (Al2SiO5) with carbonaceous inclusions

Banded Iron Formation (BIF) / Tiger Iron variety (Banded Iron Formation (composed primarily of Magnetite Fe3O4, Hematite Fe2O3, and Chert/Quartz SiO2)) — sedimentary

Banded Iron Formation (BIF) / Tiger Iron variety

Banded Iron Formation (composed primarily of Magnetite Fe3O4, Hematite Fe2O3, and Chert/Quartz SiO2)

Basalt (Water-worn Pebble) (Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Basalt (Water-worn Pebble)

Basalt (Aphanitic Mafic Igneous Rock)

Basalt (Basalt (Mafic volcanic rock)) — igneous

Basalt

Basalt (Mafic volcanic rock)

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

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Geode with Quartz Crystal Cavity (Silicon Dioxide (SiO2) in Calcareous/Siliceous Matrix) — sedimentary

Geode with Quartz Crystal Cavity

Silicon Dioxide (SiO2) in Calcareous/Siliceous Matrix

Oolite or Oolitic Limestone (Oolitic Limestone (Principal mineral: Calcite, CaCO3)) — sedimentary

Oolite or Oolitic Limestone

Oolitic Limestone (Principal mineral: Calcite, CaCO3)

Oolitic Limestone / Fossiliferous Chert (Oolitic Limestone (CaCO3) / Silicified Limestone) — sedimentary

Oolitic Limestone / Fossiliferous Chert

Oolitic Limestone (CaCO3) / Silicified Limestone

Red Sandstone (Arenite (with Iron Oxide)) — sedimentary

Red Sandstone

Arenite (with Iron Oxide)

Red Sandstone (Clastic Terrigenous Sedimentary Rock (typically Hematitic Quartz Arenite or Arkose)) — sedimentary

Red Sandstone

Clastic Terrigenous Sedimentary Rock (typically Hematitic Quartz Arenite or Arkose)

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)

River Pebble (Gravel) (Clastic sedimentary rock (likely Siltstone or Mudstone pebble; SiO2 with various impurities)) — sedimentary

River Pebble (Gravel)

Clastic sedimentary rock (likely Siltstone or Mudstone pebble; SiO2 with various impurities)

Greenstone (Greenschist (primarily composed of chlorite, actinolite, and epidote)) — metamorphic

Greenstone

Greenschist (primarily composed of chlorite, actinolite, and epidote)

Agate Slices and Clear Quartz Points (Agate (SiO2 Chalcedony) and Clear Quartz (SiO2 Crystalline)) — mineral

Agate Slices and Clear Quartz Points

Agate (SiO2 Chalcedony) and Clear Quartz (SiO2 Crystalline)

Green Fluorite (Calcium Fluoride (CaF2)) — mineral

Green Fluorite

Calcium Fluoride (CaF2)

Erythrite (Erythrite (Cobalt Bloom) - Co3(AsO4)2·8H2O) — mineral

Erythrite

Erythrite (Cobalt Bloom) - Co3(AsO4)2·8H2O

Prehnite (Prehnite, Ca2Al(AlSi3O10)(OH)2) — mineral

Prehnite

Prehnite, Ca2Al(AlSi3O10)(OH)2

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Pyrite and Sunstone (Iron Sulfide (FeS2) and Plagioclase Feldspar ((Ca,Na)Al(Al,Si)Si2O8)) — mineral

Pyrite and Sunstone

Iron Sulfide (FeS2) and Plagioclase Feldspar ((Ca,Na)Al(Al,Si)Si2O8)

Carnelian (Carnelian (SiO2)) — mineral

Carnelian

Carnelian (SiO2)

Chert (variously known as Flint or Microcrystalline Quartz) (Silicon dioxide (SiO2)) — sedimentary

Chert (variously known as Flint or Microcrystalline Quartz)

Silicon dioxide (SiO2)

Chalcedony (Desert Rose or Botryoidal Chalcedony) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Desert Rose or Botryoidal Chalcedony)

Silicon Dioxide (SiO2)

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

Red Hematite

Iron(III) oxide (Fe2O3)

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

Hematite

Iron(III) oxide (Fe2O3)

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

Hematite

Iron(III) oxide (Fe2O3)

Calcite (Calcium Carbonate (CaCO3)) — mineral

Calcite

Calcium Carbonate (CaCO3)

Orthoclase Feldspar (Orthoclase (KAlSi3O8)) — Mineral

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Labradorite (Labradorite (Plagioclase Feldspar Series) - (Ca, Na)(Al, Si)4O8) — mineral

Labradorite

Labradorite (Plagioclase Feldspar Series) - (Ca, Na)(Al, Si)4O8

Muscovite Mica (in Quartz/Feldspar Matrix) (Muscovite - KAl2(AlSi3O10)(OH)2) — mineral

Muscovite Mica (in Quartz/Feldspar Matrix)

Muscovite - KAl2(AlSi3O10)(OH)2

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

Carnelian

Carnelian (a variety of Chalcedony, SiO2)

Rose Quartz (Silicon Dioxide (SiO2)) — mineral

Rose Quartz

Silicon Dioxide (SiO2)

Carnelian (Chalcedony (Silicon Dioxide / SiO2)) — mineral

Carnelian

Chalcedony (Silicon Dioxide / SiO2)

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

Bloodstone (Heliotrope)

Silicon Dioxide (SiO2) - Variety of Chalcedony/Jasper

Blue Sapphire (Corundum (Al2O3) with traces of Iron and Titanium) — mineral

Blue Sapphire

Corundum (Al2O3) with traces of Iron and Titanium

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Chert (specifically Gray/Tan Bedded Chert) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Gray/Tan Bedded Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)