Rock Identifier

Category

Sedimentary (Secondary Formation)

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

Howlite (Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)) — mineral

Howlite

Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)

Geode (unopened) (Calcedony-lined Geode (SiO2)) — sedimentary

Geode (unopened)

Calcedony-lined Geode (SiO2)

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

Agate (or Chalcedony)

Silicon Dioxide (SiO2)

Agate (Geode nodule fragment) (Chalcedony (cryptocrystalline variety of Quartz), SiO2) — mineral

Agate (Geode nodule fragment)

Chalcedony (cryptocrystalline variety of Quartz), SiO2

Carnelian Agate (Silicon Dioxide (SiO2) with iron oxide impurities) — mineral

Carnelian Agate

Silicon Dioxide (SiO2) with iron oxide impurities

Likely red jasper or iron-rich chert fragments (Microcrystalline quartz (SiO₂), colored by hematite/goethite; exact identification requires testing) — mineral

Likely red jasper or iron-rich chert fragments

Microcrystalline quartz (SiO₂), colored by hematite/goethite; exact identification requires testing

Likely white quartz or quartz-rich pebble (Quartz (silicon dioxide, SiO₂), possibly a small polished/tumbled specimen) — mineral

Likely white quartz or quartz-rich pebble

Quartz (silicon dioxide, SiO₂), possibly a small polished/tumbled specimen

Unidentified small rock fragment (Indeterminate; appearance may be consistent with a weathered sandstone or limestone fragment) — sedimentary

Unidentified small rock fragment

Indeterminate; appearance may be consistent with a weathered sandstone or limestone fragment

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

Weathered sandstone or quartz-rich sedimentary pebble (Indeterminate lithic fragment; likely quartz arenite (sandstone)) — sedimentary

Weathered sandstone or quartz-rich sedimentary pebble

Indeterminate lithic fragment; likely quartz arenite (sandstone)

Yellow Jasper (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Yellow Jasper (Silicon Dioxide (SiO2) with iron hydroxides) — sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with iron hydroxides

Red Jasper (Quartz (SiO2) with hematite inclusions) — sedimentary

Red Jasper

Quartz (SiO2) with hematite inclusions

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

Red Jasper

Silicon Dioxide (SiO2) with Iron impurities

Chert (Black Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Black Flint)

Microcrystalline Quartz (SiO2)

Geode (Unopened) (Chalcedony Geode (Hydrated Silicon Dioxide, SiO2)) — sedimentary

Geode (Unopened)

Chalcedony Geode (Hydrated Silicon Dioxide, SiO2)

Quartz (Silicon dioxide (SiO2)) — Mineral

Quartz

Silicon dioxide (SiO2)

Chert Nodule in Limestone (Silicon Dioxide (SiO2) in Calcium Carbonate (CaCO3)) — sedimentary

Chert Nodule in Limestone

Silicon Dioxide (SiO2) in Calcium Carbonate (CaCO3)

Quartz Geode (Silicon Dioxide (SiO2)) — mineral

Quartz Geode

Silicon Dioxide (SiO2)

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

Blue Apatite

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

Jasper (Silicon dioxide (SiO2)) — sedimentary

Jasper

Silicon dioxide (SiO2)

Red Jasper (Silicon Dioxide with Iron Oxide impurities (SiO2 + Fe2O3)) — sedimentary

Red Jasper

Silicon Dioxide with Iron Oxide impurities (SiO2 + Fe2O3)

Red Jasper (Silicon dioxide (SiO2) with iron oxide inclusions) — mineral

Red Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Sandstone Concretion (Sedimentary Concretion (Quartz sand bound by mineral cement)) — sedimentary

Sandstone Concretion

Sedimentary Concretion (Quartz sand bound by mineral cement)

Sandstone Pebble (Sedimentary Rock (Quartzose Sandstone)) — sedimentary

Sandstone Pebble

Sedimentary Rock (Quartzose Sandstone)

Sandstone (Ferruginous) (Arenite (Fe2O3 enriched)) — sedimentary

Sandstone (Ferruginous)

Arenite (Fe2O3 enriched)

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

Chert (Pink Jasper variant)

Microcrystalline Quartz (SiO2)

Banded Agate (Silicon Dioxide (SiO2)) — sedimentary

Banded Agate

Silicon Dioxide (SiO2)

Limonite Geode / Ironstone Concretion with Quartz (Limonite with Quartz (FeO(OH)·nH2O + SiO2)) — sedimentary

Limonite Geode / Ironstone Concretion with Quartz

Limonite with Quartz (FeO(OH)·nH2O + SiO2)

Yellow Jasper (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Dyed Agate (Tumbled) (Silicon Dioxide (SiO2) - stained microcrystalline quartz) — sedimentary

Dyed Agate (Tumbled)

Silicon Dioxide (SiO2) - stained microcrystalline quartz

Puddingstone (Conglomerate (Gowganda Formation)) — sedimentary

Puddingstone

Conglomerate (Gowganda Formation)

Banded Iron Formation (BIF) (Banded Iron Formation) — sedimentary

Banded Iron Formation (BIF)

Banded Iron Formation

Banded Iron Formation (BIF) (Banded Iron Formation) — sedimentary

Banded Iron Formation (BIF)

Banded Iron Formation

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

Botryoidal Hematite (Iron Ore)

Iron(III) oxide (Fe2O3)

Banded Jasper (Silicon Dioxide with Iron Oxide impurities (SiO2)) — sedimentary

Banded Jasper

Silicon Dioxide with Iron Oxide impurities (SiO2)

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

Chert / Jasper

Microcrystalline Quartz (SiO2)

Satin Spar (Gypsum) (Hydrous Calcium Sulfate (CaSO4·2H2O)) — mineral

Satin Spar (Gypsum)

Hydrous Calcium Sulfate (CaSO4·2H2O)

Quartz (Silicon Dioxide (SiO2)) — mineral

Quartz

Silicon Dioxide (SiO2)

Limonite (Iron Stone Concretion) (Limonite (Hydrous Iron Oxide) - FeO(OH)·nH2O) — mineral

Limonite (Iron Stone Concretion)

Limonite (Hydrous Iron Oxide) - FeO(OH)·nH2O

Red Sandstone (Ferruginous Sandstone (SiO2 with Iron Oxide)) — sedimentary

Red Sandstone

Ferruginous Sandstone (SiO2 with Iron Oxide)

Travertine (Calcium Carbonate (CaCO3)) — sedimentary

Travertine

Calcium Carbonate (CaCO3)