Banded River Cobble with Mafic Dike
Hydrothermally altered Graywacke or Sandstone with Mafic Intrusion
igneous and sedimentary
Category
Sedimentary And Metamorphic
Browse sedimentary and metamorphic specimens identified by the Rock Identifier community.
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Limonite (Iron Ore)
Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)
mineral
Red Jasper
Jasper (Silicon Dioxide, SiO2)
mineral
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Raw selenite (gypsum)
Gypsum, CaSO₄·2H₂O; translucent variety selenite
mineral
Limonite after Pyrite (Prophecy Stone or Ironstone Concretion)
Goethite/Limonite pseudomorph after Pyrite/Marcasite (FeO(OH)·nH2O)
mineral
Pyrite on Quartz
Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)
mineral
Goethite pseudomorph after Pyrite
Goethite (FeO(OH)) pseudomorph after Pyrite (FeS2)
mineral
Quartz Vein in Sedimentary Matrix
Silicon Dioxide (SiO2) with host rock
mineral
Red Jasper (Quartzite)
Silicon Dioxide (SiO2) with iron oxide inclusions
mineral
Quartz heart (likely milky/included quartz)
Quartz, silicon dioxide (SiO₂)
mineral
Amethyst and Hematite Bracelet
Amethyst (SiO2) and Hematite (Fe2O3)
mineral
Unidentified Rock Fragment
Unknown
Rock
Mixed pebble collection, including likely flint, quartzite, and fossil material
Varied silicate rocks; visible specimen may include chert (microcrystalline SiO₂), quartzite, and a possible fossil
sedimentary
Tumbled orange chalcedony and a gray stone disk
Chalcedony (microcrystalline quartz, SiO₂); disk likely fine-grained sandstone or slate
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Pyrite-bearing rock (iron pyrite)
Pyrite, FeS₂, likely disseminated or massive in a host rock
mineral
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
mineral
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Jasper (Red Jasper)
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Pearl
Pearl; primarily aragonite (CaCO₃) in nacre
gemstone
Red Jasper
SiO2 (Silicon Dioxide with Iron inclusions)
sedimentary
Feldspar-rich Quartzite
Metamorphic Quartz-Feldspar Aggregate (SiO2 + KAlSi3O8)
metamorphic
Red Jasper (Opaque Chalcedony)
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Jasper
Silicon dioxide (SiO2)
sedimentary
Limonite Pseudomorph after Pyrite
Goethite/Limonite FeO(OH)·nH2O replacing Pyrite FeS2
mineral
Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)
Chert (microcrystalline quartz)
Metamorphic Rock
Quartz (chalcedony variety) or Limestone with Quartz Veins
SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)
Mineral or Sedimentary Rock (with mineral inclusions)
Sandstone or Quartzite
Arenite (if sedimentary) / Quartzite (if metamorphic)
Sedimentary or Metamorphic
Pyrite (or Fool's Gold)
Pyrite (FeS₂)
Mineral
Quartzite / Sandstone / Chert Mix
Silicon Dioxide (SiO2)
sedimentary and metamorphic
Tumbled reddish-brown pebble, likely sandstone or iron-rich quartzite
Probable ferruginous sandstone (quartz-rich; SiO₂ with iron oxides), possibly quartzite
sedimentary or metamorphic
Jasper
Chalcedony (Microcrystalline Quartz) - SiO2
sedimentary or metamorphic
Sandstone, Quartzite, and River Pebbles
Silicon Dioxide (SiO2) based Sedimentary/Metamorphic structures
Sedimentary and Metamorphic
Carnelian
Carnelian (a variety of Chalcedony, SiO ₂)
Mineral (specifically a variety of Chalcedony, which is a cryptocrystalline quartz)
Jasper or Red Quartzite
SiO2 (Silicon Dioxide with iron oxide impurities)
sedimentary or metamorphic
Mixed Agate and Lapis Lazuli Bracelet
Chalcedony (SiO2) and Lapis Lazuli (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2
sedimentary and metamorphic
Worn quartz-rich pebble, likely chert or quartzite
Microcrystalline quartz (SiO₂), possibly quartzite
sedimentary or metamorphic
Glacial Erratic (Sandstone/Quartzite)
Glacial Erratic specimen (likely Orthoquartzite or Feldspathic Sandstone)
sedimentary or metamorphic
Limonite-stained Quartz / Quartzite
Silicon Dioxide (SiO2) with iron hydroxides (FeO(OH)·nH2O)
sedimentary or metamorphic