Gossan (Iron Hat)
Gossan (secondary iron oxide cap)
sedimentary
Category
Sedimentary (Secondary Mineral Formation)
Browse sedimentary (secondary mineral formation) specimens identified by the Rock Identifier community.
Learn about Sedimentary (Secondary Mineral Formation) in the encyclopedia
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Limonite/Ironstone
Limonite (Hydrous ferric oxides), FeO(OH)·nH2O
sedimentary
Rose Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Geode Nodules / Keokuk Geode
Quartz / Chalcedony Geode (SiO2)
sedimentary
Chert (Flint / Jasper)
Silicon Dioxide (SiO2)
sedimentary
Chalk (Limestone variant)
Calcium Carbonate (CaCO3)
sedimentary
Chert (Vuggy Chert)
Silicon Dioxide (SiO2)
sedimentary
Limestone with Calcite Veins
Calcium Carbonate (CaCO3)
sedimentary
River Rock
Sedimentary clast
sedimentary
Iron-rich concretion (possibly limonite/goethite)
Limonite, a mixture of iron oxyhydroxides, commonly including goethite (α-FeO(OH))
sedimentary
Green Jasper Pebble
Microcrystalline Quartz (Chalcedony), SiO2
sedimentary
Hematite
Iron Oxide (Fe2O3)
mineral
Likely weathered iron-rich rock or laterite
Laterite or ferruginous sandstone; commonly dominated by goethite/hematite with quartz and clay minerals
sedimentary
Green Jasper
Silicon Dioxide (SiO2) with iron silicate inclusions
sedimentary
Limonitic Iron Ore / Goethite
Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)
sedimentary
Agate Nodule
Silicon dioxide (Chalcedony/Quartz), SiO2
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
sedimentary
Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Banded Sandstone (Beach Pebble)
Quartz Arenite Sandstone
sedimentary
Druzy Chalcedony (Agate Geode)
Silica (SiO2) - Cryptocrystalline Quartz with druzy macrocrystalline quartz
mineral
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
mineral
Agate (or Chalcedony)
Silicon Dioxide (SiO2)
mineral
Agate (Geode nodule fragment)
Chalcedony (cryptocrystalline variety of Quartz), SiO2
mineral
Banded Iron Formation
Banded Iron Formation (BIF)
sedimentary
Brecciated Jasper
Brecciated Jasper (Microcrystalline Quartz / SiO2)
sedimentary
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Red Jasper
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
sedimentary
Pyrite
Iron Pyrite (FeS2)
mineral
Limonite
FeO(OH)·nH2O (Hydrated iron oxide)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone
Arenite (SiO2 primarily)
sedimentary
Quartz crystal
Quartz (silicon dioxide, SiO₂), likely milky or drusy quartz
mineral
Weathered gray stone fragment
Undetermined; possibly limestone or sandstone
sedimentary
Jasper
Silicon Dioxide (SiO2) with impurities, microcrystalline quartz
sedimentary
Banded Iron Formation
Banded Iron Formation (BIF)
sedimentary
Iron-stained Quartz (with Limonite/Hematite)
Silicon Dioxide (SiO2) with Iron Oxide inclusions (FeO(OH) or Fe2O3)
Mineral
Shale with Quartz Vein
Argillaceous Shale with Silicon Dioxide Vein
sedimentary
Limonite / Goethite Ironstone
FeO(OH)·nH2O (Hydrous iron oxide)
mineral
Sandstone Pebble
Sedimentary Rock (Quartzose Sandstone)
sedimentary
Sandstone with Quartz Veining
Arenite with SiO2 veins
sedimentary