Rock Identifier

Category

Organic (Sedimentary Context)

Browse organic (sedimentary context) specimens identified by the Rock Identifier community.

Learn about Organic (Sedimentary Context) in the encyclopedia

Sapropel

Bituminous Shale

Bituminous Shale

Black Shale

Oil Shale

Yellow Jasper (Chalcedony (SiO2) with iron oxide inclusions) — mineral

Yellow Jasper

Chalcedony (SiO2) with iron oxide inclusions

Yellow Chert (Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Yellow Chert (Jasper)

Silicon Dioxide (SiO2)

Chalcedony Geode / Agate Nodule (Cryptocrystalline Quartz (SiO2)) — mineral

Chalcedony Geode / Agate Nodule

Cryptocrystalline Quartz (SiO2)

Red Sandstone (Clastic Terrigenous Sedimentary Rock (primarily SiO2 with Fe2O3 coating)) — sedimentary

Red Sandstone

Clastic Terrigenous Sedimentary Rock (primarily SiO2 with Fe2O3 coating)

Flint or chert (Microcrystalline quartz (SiO₂), commonly chalcedony with possible impurities) — sedimentary

Flint or chert

Microcrystalline quartz (SiO₂), commonly chalcedony with possible impurities

Rounded sandstone pebble (Clastic sandstone, predominantly quartz (SiO₂) grains in a cementing matrix) — sedimentary

Rounded sandstone pebble

Clastic sandstone, predominantly quartz (SiO₂) grains in a cementing matrix

Veined gneiss (Felsic to mafic banded gneiss, chiefly quartz–feldspar–biotite/hornblende) — metamorphic

Veined gneiss

Felsic to mafic banded gneiss, chiefly quartz–feldspar–biotite/hornblende

Sandstone (Ferruginous Concretion) (Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement) — sedimentary

Sandstone (Ferruginous Concretion)

Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement

Metal Chain (Likely Steel or a Steel Alloy) (Steel (primarily iron and carbon); specific alloy unknown) — Man-made Object (Metal/Alloy)

Metal Chain (Likely Steel or a Steel Alloy)

Steel (primarily iron and carbon); specific alloy unknown

Man-made Object (Metal/Alloy)

Ferruginous Sandstone (with Laterite) (Ferruginous Arenite (FeO(OH)·nH2O)) — sedimentary

Ferruginous Sandstone (with Laterite)

Ferruginous Arenite (FeO(OH)·nH2O)

Sandstone Concretion (Sandstone (Sedimentary Rock) with silica or calcite cement) — sedimentary

Sandstone Concretion

Sandstone (Sedimentary Rock) with silica or calcite cement

Pyrite (Pyrite (FeS₂)) — Mineral

Pyrite

Pyrite (FeS₂)

Mixed gravelly conglomeratic road aggregate (Polymictic clast-supported conglomerate or fill; composition varies, commonly quartz, feldspar, basalt, and weathered rock fragments) — sedimentary

Mixed gravelly conglomeratic road aggregate

Polymictic clast-supported conglomerate or fill; composition varies, commonly quartz, feldspar, basalt, and weathered rock fragments

Mica Schist (Mica Schist (Quartz-Mica Schist)) — metamorphic

Mica Schist

Mica Schist (Quartz-Mica Schist)

Chert (Nodule) (Chert (variety of microcrystalline quartz, SiO2)) — sedimentary

Chert (Nodule)

Chert (variety of microcrystalline quartz, SiO2)

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

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Ironstone Concretion (Limonite/Goethite) (Ferruginous Sandstone or Limonite (FeO(OH)·nH2O)) — sedimentary

Ironstone Concretion (Limonite/Goethite)

Ferruginous Sandstone or Limonite (FeO(OH)·nH2O)

Quartz-rich hydrothermal vein rock, possibly quartzite (Mostly SiO₂ (quartz), with probable iron oxides and minor sulfides) — metamorphic

Quartz-rich hydrothermal vein rock, possibly quartzite

Mostly SiO₂ (quartz), with probable iron oxides and minor sulfides

Weathered conglomeratic sandstone (Polymictic conglomerate or pebbly sandstone, likely iron-stained) — sedimentary

Weathered conglomeratic sandstone

Polymictic conglomerate or pebbly sandstone, likely iron-stained

Weathered chert (flint) pebble (Microcrystalline quartz/chalcedony (SiO₂), commonly with iron-oxide staining) — sedimentary

Weathered chert (flint) pebble

Microcrystalline quartz/chalcedony (SiO₂), commonly with iron-oxide staining

River Cobble (Conglomerate context) (Unconsolidated Fluvial Alluvium (comprised of various lithologies like Quartzite, Granite, or Basalt)) — sedimentary

River Cobble (Conglomerate context)

Unconsolidated Fluvial Alluvium (comprised of various lithologies like Quartzite, Granite, or Basalt)

Flint or chert projectile point (Microcrystalline quartz (SiO₂), likely chalcedony-rich chert) — sedimentary

Flint or chert projectile point

Microcrystalline quartz (SiO₂), likely chalcedony-rich chert

Sandstone Concretion (Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)) — sedimentary

Sandstone Concretion

Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)

Red Jasper (River Siltstone) (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Red Jasper (River Siltstone)

Silicon Dioxide (SiO2) with iron oxide inclusions

Ironstone Concretion (Limonitic/Hematitic Concretion) — sedimentary

Ironstone Concretion

Limonitic/Hematitic Concretion

Jasper with Iron Staining (Silicon Dioxide (SiO2) with impurities) — sedimentary

Jasper with Iron Staining

Silicon Dioxide (SiO2) with impurities

Quartz Geode (Silicon Dioxide (SiO2)) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2)

Flint or chert flake (Microcrystalline quartz (SiO₂), commonly chalcedony with possible impurities) — sedimentary

Flint or chert flake

Microcrystalline quartz (SiO₂), commonly chalcedony with possible impurities

Yellow Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

Jasper (Red Jasper) (Silicon Dioxide (SiO₂)) — sedimentary

Jasper (Red Jasper)

Silicon Dioxide (SiO₂)

Ferruginous Sandstone (Ironstone) (Sandstone with Hematite/Goethite cement (SiO2 + FeO(OH))) — sedimentary

Ferruginous Sandstone (Ironstone)

Sandstone with Hematite/Goethite cement (SiO2 + FeO(OH))

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

Hematite

Iron(III) oxide (Fe2O3)

Red Jasper (Opaque microcrystalline Quartz (SiO2 with Fe2O3 inclusions)) — sedimentary

Red Jasper

Opaque microcrystalline Quartz (SiO2 with Fe2O3 inclusions)

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)

Fluorite (Fluorite (Calcium Fluoride, CaF2)) — mineral

Fluorite

Fluorite (Calcium Fluoride, CaF2)

Leopard Skin Jasper (SiO2 (Microcrystalline Quartz with inclusions)) — mineral

Leopard Skin Jasper

SiO2 (Microcrystalline Quartz with inclusions)

Ferruginous Conglomerate (Ferruginous Conglomerate (Clastic Sedimentary Rock)) — sedimentary

Ferruginous Conglomerate

Ferruginous Conglomerate (Clastic Sedimentary Rock)

Gneiss (specifically a water-worn pebble) (Gneiss) — metamorphic

Gneiss (specifically a water-worn pebble)

Gneiss

Shale creek bed (Shale (fine-grained clastic sedimentary rock)) — Sedimentary

Shale creek bed

Shale (fine-grained clastic sedimentary rock)

Quartz (Quartz (SiO2)) — Mineral

Quartz

Quartz (SiO2)

Fossilized Shell Fragment (Invertebrate marine fossil, likely calcium carbonate replacement) — fossil

Fossilized Shell Fragment

Invertebrate marine fossil, likely calcium carbonate replacement

Magnetite (Magnetite (Fe3O4)) — Mineral

Magnetite

Magnetite (Fe3O4)