Pyrite
Iron Sulfide (FeS2)
Category
Browse sedimentary or metamorphic (low grade) specimens identified by the Rock Identifier community.
Pyrite
Iron Sulfide (FeS2)
Garnet in Schist (Mica Schist with Garnet Inclusion)
Garnetiferous Mica Schist (X3Al2(SiO4)3)
Greenschist with Quartz Veining
Greenschist (commonly containing Chlorite, Actinolite, and Epidote)
Ironstone Concretion (Coprolite-like)
Goethite/Hematite Siderite Spheroid (FeCO3 or FeO(OH))
Quartz (specifically Milky Quartz or Quartzite)
Silicon Dioxide (SiO2)
Bauxite
Aluminium ore consisting largely of the minerals gibbsite Al(OH)3, boehmite γ-AlO(OH) and diaspore α-AlO(OH)
Coal
Bituminous or Anthracite Coal
Limonite (Ironstone)
Limonite (FeO(OH)·nH2O)
Coal (specifically Bituminous or Anthracite)
Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N
Aquamarine
Beryllium aluminum silicate (Be3Al2Si6O18)
Carnelian
Silicon Dioxide (Chalcedony variety), SiO2
Red Jasper Pebble
Microcrystalline Quartz (Chalcedony), SiO2
Conglomerate
Conglomerate
Quartz Pebble
Crystalline Silica (SiO2)
Limonite Concretion
FeO(OH)qnH2O (Hydrated iron(III) oxide-hydroxide mixture)
Limonite-stained Gossan/Ironstone
Goethite and Hematite (Fe2O3 • nH2O)
Limonite (Iron Ore)
Hydrated ferric oxide (FeO(OH)·nH2O)
Ironstone Concretion (Limonite/Goethite)
Iron oxide concretion (contains FeO(OH)·nH2O)
Concretion
Siderite or Ironstone Concretion
Quartz-Veined Mudstone
Argillite or Mudstone with Quartz Veining (SiO2 in Siliciclastic Matrix)
Sandstone (Ferruginous Concretion)
Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement
Ferruginous Sandstone
Arenite with limonite/goethite cement
Ferruginous Sandstone (Ironstone)
Clastic Sedimentary Rock (composed of SiO2 with Fe2O3/FeO(OH) cement)
Ferruginous Sandstone
Arenite with Iron-Oxide Cement
Ferruginous Sandstone Concretion (Ironstone Phosphorite)
Ferruginous Sandstone (variable Fe-oxide/hydroxide composition)
Milky Quartz
Silicon Dioxide (SiO2)
Siltstone
Siltstone (primarily SiO2 with Al2O3)
Emerald in Matrix
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
Anthracite Coal
Anthracite (Carbon-rich metamorphic rock)
Corundum (Sapphire/Ruby in Matrix)
Aluminium oxide (Al2O3)
Lapis Lazuli (Low Quality/Rough)
Lapis Lazuli (comprised of Lazurite, Calcite, and Pyrite)
Limonite (Ironstone) Concretion
FeO(OH)·nH2O (Hydrous ferric oxide)
Limonite Concretion (Ironstone)
Limonite / Goethite (FeO(OH)·nH2O)
Ironstone Concretion
Goethite-rich Siltstone / Siderite (FeCO3)
Ironstone Concretion (Siderite Nodules)
Siderite (FeCO3) in Mudstone or Sandstone matrix
Ferruginous Sandstone
Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)
Ironstone Concretion
Siderite or Hematite Concretion (FeCO3 or Fe2O3)
Siltstone
Siltstone
Red Jasper
Microcrystalline Quartz (SiO2)
Jadeite Ring
Jadeite (NaAlSi2O6)
Corundum (Sapphire variant)
Aluminium oxide (Al2O3)
Jadeite Jade
NaAlSi2O6 (Sodium Aluminum Silicate)