Pyrite
Iron Sulfide (FeS2)
mineral
Category
Sedimentary (With Some Aspects Of Mineral Replacement)
Browse sedimentary (with some aspects of mineral replacement) specimens identified by the Rock Identifier community.
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Geode / Fossilized Gastropod or Shell Cast
Silicon dioxide (Quartz) replacement / fossil mold
sedimentary
Jasper or Agate (Chalcedony)
Silicon Dioxide (SiO2) with impurities
sedimentary
Concretion in Shale
Siltstone/Shale with Siderite or Calcareous concretions
sedimentary
Moqui Marble (Shaman Stone)
Iron Oxide Concretion (Goethite/Hematite shell with Sandstone core)
sedimentary
Fluorite (translucent octahedral crystal)
Calcium fluoride (CaF2)
mineral
Gneiss
Metamorphic Gneiss (High-grade regional metamorphism)
metamorphic
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Chalcedony (possibly agate or common quartz)
Microcrystalline quartz, SiO₂
mineral
Chert Nodule
Microcrystalline Quartz (SiO2)
sedimentary
Coprolite
Coprolite (fossilized feces)
sedimentary
Chert (within Limestone)
Silicon Dioxide (SiO2) in Calcium Carbonate (CaCO3) matrix
sedimentary
Garnet (Almandine)
Almandine (Fe3Al2(SiO4)3)
mineral
Potassium Feldspar
Orthoclase (KAlSi3O8)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Chert / Fossiliferous Limestone
Sedimentary Chert (often containing CaCO3 or SiO2 replacements)
sedimentary
Fossilized Brachiopod
Brachiopoda (e.g., Atrypa or Rhynchonellida)
fossil
Ironstone (Limonite/Hematite concretion)
Ferruginous Siltstone / Goethite (FeO(OH))
sedimentary
Fossil Belemnite Guard
Belemnitella spp. (rostrum)
fossil
Magnetite (Lodestone)
Magnetite (Fe3O4)
mineral
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Fossilized Bone
Vertebrate Fossil Fragment (Calcium Phosphate / Hydroxyapatite)
fossil
Chert (or Flint)
Silicon dioxide (SiO2)
sedimentary
Sandstone
Arenite
sedimentary
Selenite (variety of Gypsum)
Calcium sulfate dihydrate (CaSO4·2H2O)
mineral
Gneiss
Gneiss (foliated metamorphic rock)
metamorphic
Flint / Chert with Cortex
Microcrystalline Quartz (SiO2)
sedimentary
Limonite-stained Chert
Microcrystalline Quartz (SiO2) with Goethite/Limonite (FeO(OH)·nH2O)
sedimentary
Muscovite Schist
KAl2(AlSi3O10)(OH)2 (Muscovite) in Schist Matrix
metamorphic
Chert with Chalcedony/Quartz Vug
Cryptocrystalline Silica (SiO2)
sedimentary
Jasper (Banded Argillite/Chert mix)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Amber
Succinicum (C10H16O)
mineral
Flint
SiO2 (Microcrystalline Quartz / Chert)
sedimentary
Fossilized Echinoid (Sea Urchin)
Echinoidea (Fossil)
sedimentary
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Limonitic Chert)
Microcrystalline Quartz (SiO2)
sedimentary
Feldspar
KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8
mineral
Fossilized Shark Teeth
Carcharhiniformes or Lamniformes species (common mineral: Fluorapatite/Ca5(PO4)3F)
sedimentary (fossilized organic matter)
Yellow Chert (Gold-colored River Pebble)
Microcrystalline Quartz (SiO2) with Limonite/Goethite staining
sedimentary
Petrified Wood
Silicified wood (primarily SiO2)
sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Magnetite
Magnetite (Iron(II,III) oxide, Fe3O4)
mineral