Rock Identifier

Category

Sedimentary Or Igneous (Secondary Formation)

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

Basalt (Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Basalt (Mafic Igneous Rock (primarily Plagioclase and Pyroxene)) — igneous

Basalt

Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

Obsidian (Volcanic Glass (Amorphous Silicon Dioxide , SiO2)) — igneous

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide , SiO2)

Quartz (likely Yellow/Orange variety, possibly Citrine or Chalcedony with iron staining) (Quartz (SiO₂)) — Mineral

Quartz (likely Yellow/Orange variety, possibly Citrine or Chalcedony with iron staining)

Quartz (SiO₂)

River Pebble (Likely Chert or Fine-Grained Sandstone/Quartzite) (Siliciclastic clast (likely Chert or Quartzarenite/Quartzite pebble)) — Sedimentary

River Pebble (Likely Chert or Fine-Grained Sandstone/Quartzite)

Siliciclastic clast (likely Chert or Quartzarenite/Quartzite pebble)

Sandstone (Ferruginous) (Arenite (primarily SiO2 with iron oxide cement)) — sedimentary

Sandstone (Ferruginous)

Arenite (primarily SiO2 with iron oxide cement)

Sandstone (Ferruginous) (Arenite with Iron-Oxide Cement) — sedimentary

Sandstone (Ferruginous)

Arenite with Iron-Oxide Cement

Sandstone (Arenite) — sedimentary

Sandstone

Arenite

Sandstone (Arenite (Siliclastic sedimentary rock), SiO2 + various minerals) — sedimentary

Sandstone

Arenite (Siliclastic sedimentary rock), SiO2 + various minerals

Granite (Plutonic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)) — igneous

Granite

Plutonic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)

Red Jasper (Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions) — sedimentary

Red Jasper

Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions

Epidote (or Epidote-rich rock) (Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).) — Mineral, often found in metamorphic rocks but also in sedimentary and igneous rocks

Epidote (or Epidote-rich rock)

Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).

Mineral, often found in metamorphic rocks but also in sedimentary and igneous rocks

Sandstone (Arenite (primarily SiO2)) — sedimentary

Sandstone

Arenite (primarily SiO2)

Sandstone (Arenite (primarily SiO2)) — sedimentary

Sandstone

Arenite (primarily SiO2)

Ferruginous Sandstone (with ripple marks) (Arenite with Iron-Oxide (Fe2O3) cement) — sedimentary

Ferruginous Sandstone (with ripple marks)

Arenite with Iron-Oxide (Fe2O3) cement

Red Siltstone (or Red Shale) (Clastic Sedimentary Rock (Composition: primarily Quartz, Clay minerals, and Hematite Fe2O3)) — sedimentary

Red Siltstone (or Red Shale)

Clastic Sedimentary Rock (Composition: primarily Quartz, Clay minerals, and Hematite Fe2O3)

Yellow Chert (Sedimentary cryptocrystalline quartz (SiO2)) — sedimentary

Yellow Chert

Sedimentary cryptocrystalline quartz (SiO2)

Limestone (Calcareous Sedimentary Rock (CaCO3)) — sedimentary

Limestone

Calcareous Sedimentary Rock (CaCO3)

Basalt (Extrusive Mafic Igneous Rock) — igneous

Basalt

Extrusive Mafic Igneous Rock

Red Sandstone (Arenite (Ferruginous Sandstone)) — sedimentary

Red Sandstone

Arenite (Ferruginous Sandstone)

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

Hematite

Iron(III) oxide (Fe2O3)

Basalt (Extrusive Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)) — igneous

Basalt

Extrusive Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)

Sandstone (Sandstone (composed primarily of sand-sized minerals or rock grains)) — sedimentary

Sandstone

Sandstone (composed primarily of sand-sized minerals or rock grains)

Pink Granite (Phaneritic Felsic Igneous Rock (Granite)) — igneous

Pink Granite

Phaneritic Felsic Igneous Rock (Granite)

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

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Granite with Quartz Vein (Phaneritic Felsic Igneous Rock (composed of Quartz [SiO2], Feldspar, and Mica)) — igneous

Granite with Quartz Vein

Phaneritic Felsic Igneous Rock (composed of Quartz [SiO2], Feldspar, and Mica)

Sandstone (Quartzite Pebble) (Arenite / Metamorphosed Sandstone (SiO2)) — sedimentary

Sandstone (Quartzite Pebble)

Arenite / Metamorphosed Sandstone (SiO2)

Fossilized Turritella Gastropod (Internal Mold) (Turritella (Fossil Gastropod Crust)) — sedimentary

Fossilized Turritella Gastropod (Internal Mold)

Turritella (Fossil Gastropod Crust)

Ironstone Concretion (Pot Stone) (Siderite or Limonite Concretion (FeCO3 or FeO(OH)·nH2O)) — sedimentary

Ironstone Concretion (Pot Stone)

Siderite or Limonite Concretion (FeCO3 or FeO(OH)·nH2O)

Chert (Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Pink Jasper/Agate variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Pink Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Chert (Yellow Jasper variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

Chert (Flint variety) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Flint variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

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

Chert (Jasper/Flint variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Jasper (likely a variety of Brecciated Jasper or a patterned variety) (Silicon dioxide (SiO2)) — Mineral

Jasper (likely a variety of Brecciated Jasper or a patterned variety)

Silicon dioxide (SiO2)

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

White Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Red Sandstone (Arenite (Ferruginous Sandstone)) — sedimentary

Red Sandstone

Arenite (Ferruginous Sandstone)

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

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Black Spinel (Magnesium Aluminum Oxide (MgAl2O4)) — mineral

Black Spinel

Magnesium Aluminum Oxide (MgAl2O4)

Green Aventurine (Quartz (Silicon Dioxide) with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)) — mineral

Green Aventurine

Quartz (Silicon Dioxide) with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)