Limonite after Pyrite (Prophecy Stone)
Limonite (FeO(OH)·nH2O) replacing Pyrite (FeS2)
Mineral pseudomorph
Category
Anthropogenic (Man Made Material Processed By Nature)
Browse anthropogenic (man made material processed by nature) specimens identified by the Rock Identifier community.
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Chert (Nodular or Massive Variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Iron-stained Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
mineral
Synthetic Sapphire and Ion-X Glass
Single-crystal Alumina (Al2O3) and Ion-strengthened Aluminosilicate Glass
mineral
Fulonite (Fulgurite-like)
Fulgurite (SiO2 fused silica/lechatelierite)
Metamorphic (Pseudo-igneous)
White Topaz
Topaz - Al2SiO4(F,OH)2
mineral
Jasper with Quartz inclusions
Silicon Dioxide (SiO2) - Microcrystalline Chalcedony
sedimentary
Banded Calcite or Travertine
Calcium Carbonate (CaCO3)
Sedimentary
Blue Onyx (Dyed Agate)
Cryptocrystalline Quartz (SiO2) with artificial pigment
mineral
Travertine (used in construction, not a 'specimen' in situ)
Travertine
Sedimentary
Jasper
Silicon Dioxide (SiO2) with impurities (mostly Iron Oxides)
sedimentary
Honey Calcite (Yellow Calcite)
Calcium Carbonate (CaCO3)
mineral
Gneiss
Gneiss (a rock type, not a specific mineral with a formula)
Metamorphic Rock
Schorl (Black Tourmaline)
Sodium Iron Aluminum Borosilicate Hydroxide - NaFe2+3Al6Si6O18(BO3)3(OH)3OH
mineral
Porcelain (Stoneware Ceramic)
Mullite / Silica-glass composite (Al6Si2O13)
metamorphic (man-made)
Glass Nugget (Tumbled Glass)
Amorphous Silicon Dioxide (SiO2) with additives
mineraloid (man-made)
Granite
Granite (felsic intrusive igneous rock)
igneous
Gold
Native Gold (Au)
mineral
Chert (Grey-Green Flint)
Microcrystalline silicon dioxide (SiO2)
sedimentary
Fuchsite Quartzite
Fuchsite-bearing Quartzite
Metamorphic
Coquina
Biogenic Limestone (Calcium Carbonate - CaCO3)
sedimentary
Dyed Agate (Tumbled)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
mineral
Slag Glass (Cullet)
Amorphous Silica / Glass residue
Man-made byproduct (Non-geological)
N/A - Image is non-geological
Acrylonitrile Butadiene Styrene (ABS) or Polypropylene (PP)
Synthetic material (Plastic/Polymer)
Olivine (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4
mineral
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Celestite (Celestine)
Strontium sulfate (SrSO4)
mineral
Synthetic Zinc/Polycarbonate Composite (Bey-specimen)
Zinc Alloy (Zamak 3) with Polycarbonate (C15H16O2)n Overlay
Anthropogenic Mineral Mimic
Ferro-Manganese Slag
Vitreous Silicate Slag
Anthropogenic (Industrial byproduct)
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
mineral
Jade (Nephrite or Jadeite)
Nephrite: Ca2(Mg,Fe)5Si8O22(OH)2 (amphibole mineral); Jadeite: NaAlSi2O6 (pyroxene mineral)
Metamorphic Rock / Mineral
Jasper
Jasper (Silicon Dioxide, SiO2 with iron inclusions)
sedimentary
Common Marble
Calcium Carbonate (CaCO3)
metamorphic
United States Quarter Dollar
Cupronickel Clad Alloy (75% Copper, 25% Nickel over a 100% Copper core)
Metal / Man-made mineral-like object
Cobalt Blue Sea Glass
Amorphous Silica Glass (SiO2 + CoO)
mineraloid / anthropogenic material
Schorl (Black Tourmaline)
Schorl (Sodium Iron Aluminum Borosilicate Hydroxide), NaFe3Al6(BO3)3Si6O18(OH)4
mineral
Schorl (Black Tourmaline)
NaFe3Al6(BO3)3Si6O18(OH)4 (Complex Borosilicate)
mineral
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
sedimentary
Chert (Iron-stained)
Chert (Microcrystalline and Cryptocrystalline Quartz, SiO2)
sedimentary
Jasper
Silicon Dioxide (SiO2) - Impure Variety of Chert
sedimentary