Limonite Concretion (Ironstone)
Limonite (FeO(OH)·nH2O) / Goethite
Category
Browse marble specimens identified by the Rock Identifier community.
Limonite Concretion (Ironstone)
Limonite (FeO(OH)·nH2O) / Goethite
Sandstone with Ironstone Concretion
Arenite with Hematite/Goethite nodules (Fe2O3 / FeO(OH))
Sandstone Concretion
Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)
Charoite
(K,Sr,Ba,Ca)15-16(Na,Ca)8(Si,Al)24O60(OH,F)4 · nH2O (Hydrated silicate of potassium, calcium, and sodium)
Sandstone Concretion
Ferruginous Sandstone Concretion
Ironstone Concretion / Limonite
Goethite and Limonite (FeO(OH)·nH2O)
Orange Calcite
Calcium Carbonate (CaCO3)
Sandstone Chert Concretion
Silica-cemented Concretion (primarily SiO2)
Ferruginous Sandstone (Ironstone Nodules)
Ferruginous Quartz-Arenite (with Goethite/Hematite cement)
Ironstone Concretion (Limonite/Goethite)
Ferruginous Sandstone or Limonite (FeO(OH)·nH2O)
Ferruginous Sandstone (Ironstone Nodules)
Ferruginous Sandstone with Limonite/Goethite coating (Fe2O3·H2O)
Ironstone Concretion
Siderite or Hematite-bonded Concretion
Lapis Lazuli
Lapis Lazuli (Complex aggregate of Lazurite (Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2, Pyrite, and Calcite)
Blue Apatite
Fluoroapatite (Ca5(PO4)3F)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Blue Apatite
Apatite (Group), Ca5(PO4)3(F,Cl,OH)
Mica
Phlogopite or Biotite group (KMg3(AlSi3O10)(F,OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)
Sodalite
Na8(Al6Si6O24)Cl2
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
Ruby
Corundum (Al2O3 with Chromium traces)
Black Tourmaline
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
Ruby
Corundum (Al2O3 with Chromium traces)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Tourmaline
Complex Borosilicate - Na(Li,Al)3Al6(BO3)3Si6O18(OH)4 (Elbaite species)
Ruby (Corundum)
Corundum (Aluminum Oxide) with chromium trace elements, Al2O3
Lapis Lazuli
Tectosilicate (Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2
Green Calcite
Calcium Carbonate (CaCO3)
Ruby
Corundum (Al2O3 with Chromium traces)
Blue Sapphire
Corundum (Al2O3)
Ruby
Corundum (Al2O3 with Chromium)
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Acrylic or Resin (Synthetic Imitation)
Polymethyl Methacrylate (PMMA) or Polyepoxide
Sodalite
Sodalite - Na8(Al6Si6O24)Cl2
Rough Corundum (likely Sapphire/Zircon-bearing)
Aluminium Oxide (Al2O3)
Sapphire
Corundum (Al2O3)
Rough Ruby
Corundum (Al2O3 with Chromium impurities)
Yellow Apatite Sphere (Polished)
Fluorapatite / Ca5(PO4)3F
White Jade (Nephrite or Jadeite)
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2) or Jadeite (NaAlSi2O6)
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
Nephrite Jade
Calcium Magnesium Iron Silicate Hydroxide - Ca2(Mg,Fe)5Si8O22(OH)2