Limonite (Iron Stone Concretion)
Limonite (Hydrous Iron Oxide) - FeO(OH)·nH2O
mineral
Category
Sedimentary Or Metamorphic (Low Grade)
Browse sedimentary or metamorphic (low grade) specimens identified by the Rock Identifier community.
Quartzite with Chlorite
Metamosphosed Quartz Sandstone (SiO2 with (Mg,Fe)3(Si,Al)4O10(OH)2 inclusions)
metamorphic
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Rough Gemstone Grains (Mixed Sapphires and Quartz)
Corundum (Al2O3) and Quartz (SiO2)
mineral
Ironstone (likely siderite or goethite-rich siltstone)
Ferruginous Siltstone
sedimentary
Ironstone Pebble
Ferruginous sedimentary rock (Fe2O3 / FeO(OH) mixed with SiO2)
sedimentary
Nephrite Jade
Nephrite (a variety of the Calcium magnesium iron silicate mineral series Actinolite), Ca2(Mg, Fe)5Si8O22(OH)2
metamorphic
Anthracite Coal
Anthracite
metamorphic
Ruby (Corundum)
Aluminium oxide (Al2O3) with Chromium traces
mineral
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Ironstone Concretion / Limonite
Goethite and Limonite (FeO(OH)·nH2O)
sedimentary
Quartz with Chlorite or Hornblende inclusions
Silicon dioxide (SiO2) with phyllosilicate or amphibole inclusions
metamorphic
Ferruginous Sandstone
Sandstone (arenite) with Limonite/Goethite cement
sedimentary
Jadeite Jade
NaAlSi2O6 (Sodium Aluminum Silicate)
metamorphic
Greenstone
Greenschist (metamorphosed mafic igneous rock)
metamorphic
Jadeite Jade
NaAlSi2O6 (Sodium Aluminum Silicate)
metamorphic
Pyrite
Iron Sulfide (FeS2)
mineral
Siltstone
Siltstone (primarily composed of microcrystalline Quartz and Feldspar)
sedimentary
Ironstone (Limonitic Concretion)
Limonite (FeO(OH)·nH2O) with Goethite and Hematite inclusions
sedimentary
Almandine Garnet in Schist
Almandine Garnet (Fe3Al2(SiO4)3) in Mica Schist
metamorphic
Black Opal
Hydrated Silica (SiO2·nH2O)
mineral
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)
metamorphic
Eclogite
Eclogite
metamorphic
Schist
Mica Schist (primarily Muscovite or Biotite sheet silicates)
metamorphic
Schist
Mica Schist
metamorphic
Serpentine
Serpentinite (group of minerals including Antigorite, Lizardite, or Chrysotile) (Mg, Fe)3Si2O5(OH)4
metamorphic
Sandstone (Quartzite-rich)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Milky Quartz (Quartz Vein)
Silicon Dioxide (SiO2)
mineral
Red Siltstone
Siltstone (primarily quartz and feldspar sized 0.0039 to 0.0625 mm)
sedimentary
Eclogite
Eclogite (Omphacite + Almandine-Pyrope Garnet)
metamorphic
Limonite (Ironstone Concretion)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
mineral
Anthracite
Anthracite (highest-grade coal)
metamorphic
Ferruginous Sandstone (Ironstone)
Sedimentary rock with Limonite/Goethite cement
sedimentary
Limonite Sandstone
Ferruginous Sandstone (Hydrated Iron Oxide)
sedimentary
Coal (specifically Bituminous or Anthracite)
Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N
sedimentary
Limonite (Ironstone)
Limonite (FeO(OH)·nH2O)
mineral
Rough Sapphire
Corundum (Al2O3)
mineral
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
metamorphic
Nephrite Jade / Pounamu
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
metamorphic
Slate
Foliated Metamorphic Rock (primarily composed of Muscovite, Chlorite, and Quartz)
metamorphic
Anthracite Coal
Anthracite
metamorphic
Red Jasper (Chert)
Silicon dioxide (SiO2) with iron oxide inclusions
sedimentary