Sandstone with Iron Oxide Concretion
Arenite with Hematite/Goethite Concretion
sedimentary
Category
Mineral (Silicate Replaced Organic Material)
Browse mineral (silicate replaced organic material) specimens identified by the Rock Identifier community.
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Sandstone
Arenite (primarily Quartz, SiO2)
sedimentary
Tiger's Eye (Blue-Gold transition)
Pseudomorph of Quartz after Crocidolite (SiO2)
metamorphic
Tiger's Eye
SiO2 (Silicon Dioxide with inclusions of Goethite/Limonite)
Metamorphic
Fossil Shark Tooth
Carcharhinidae or Lamniformes sp. (possibly Carcharodon or Otodus genus)
fossil
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
metamorphic
United States Quarter Dollar
Cupronickel Clad Alloy (75% Copper, 25% Nickel over a 100% Copper core)
Metal / Man-made mineral-like object
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary
Fairy Stone (Menilite Concretion)
Carbonate-rich concretion (often Siderite or Calcite in Clay)
sedimentary
Glauconitic Sandstone
Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
sedimentary
Chert (Flint)
Chert (SiO2)
sedimentary
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
mineral
Moss Agate
Silicon dioxide (SiO2) with inclusions
Mineral
Tiger's Eye
Quartzo-fibrous crocidolite (SiO2 with inclusions of FeOOH)
mineral
Tiger's Eye
Silicon Dioxide (SiO2) with Limonite/Goethite inclusions
mineral
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Basalt with Quartz/Calcite matrix
Basalt (SiO2 with Ca/Mg/Fe silicates) on a Mineral Matrix
igneous
Ironstone Concretion
Siderite or Limonite Concretion (FeCO3 or FeO(OH)·nH2O)
sedimentary
Limonite (Iron Ore)
FeO(OH)·nH2O
mineral
Brown Quartz (Jasper or Chert)
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Veined Limestone (Micrite) with Quartz/Calcite Veins
Calcium Carbonate (CaCO3) with Silicate or Carbonate inclusions
sedimentary
Sandstone
Arenite (SiO2 principal)
sedimentary
Olivine (Peridotite)
(Mg, Fe)2SiO4 (Magnesium Iron Silicate)
igneous
Fossilized Dinosaur Skull (Tyrannosaurus rex)
Tyrannosaurus rex (permineralized fossil), rich in Hydroxylapatite/Silica
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (with Concretion)
Arenite / Quartzose Sandstone
sedimentary
Banded Calcite (Mexican Onyx)
Calcium Carbonate (CaCO3)
sedimentary
Tiger's Eye
Pseudomorph of quartz after crocidolite (SiO2)
metamorphic
Sandstone
Arenite (SiO2 based)
sedimentary
Moss Agate
Agate (Silicon Dioxide, SiO2) with dendritic inclusions
sedimentary
Green Moss Agate
Silicon Dioxide (SiO2) with Mineral Inclusions
sedimentary
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide
mineral
Fuchsite
Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)
mineral
Quartz / Quartzite
Silicon Dioxide (SiO2)
Mineral / Metamorphic
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Sandstone (likely Graywacke or Lithic Arenite)
Clastic sedimentary rock predominantly composed of silicate grains
sedimentary
Chalcedony (Agate)
Silicon Dioxide (SiO2)
mineral
Moss Agate
Silicon Dioxide with inclusions (SiO2)
mineral
Sandstone (Quartz Arenite)
Sandstone (dominated by SiO2 quartz grains)
sedimentary