Sedimentary Or Metamorphic (Low Grade)

Jadeite (Jade)

Jadeite (NaAlSi2O6)

Coquina / Shelly Sandstone

Calcareous Sandstone / Coquina

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals, Mg3Si2O5(OH)4)

Quartz with Chlorite / Greenschist

Quartz vein in Greenschist (SiO2 with Chlorite group minerals)

Anthracite Coal

Anthracite (Carbon)

Limonite Concretion

Limonite (Hydrated Iron Oxide) FeO(OH)·nH2O

Anthracite Coal

Anthracite (Carbon Content: 86%-97%)

Iron-Stained Quartz

Silicon Dioxide (SiO2) with Iron Oxide impurities

Limonite (Goethite/Ironstone)

Hydrated iron oxide-hydroxide, approximately FeO(OH)·nH2O

Ironstone Nodules in Chalk/Limestone

Limonite/Goethite concretions (FeO(OH)·nH2O) in Calcium Carbonate matrix (CaCO3)

Conglomerate

Conglomerate Rock

Ironstone Concretion

Ferruginous Sandstone / Siderite Concretion

Ironstone Concretion

Ironstone (Siderite/Limonite/Goethite)

Ironstone Concretion (Limonite/Goethite)

Ironstone (composed primarily of Goethite FeO(OH) and Limonite)

Limonite Concretion

Limonite (FeO(OH)·nH2O)

Ironstone Concretion / Limonite Specimen

Goethite and Limonite (Hydrous Iron Oxides)

Ferruginous Sandstone (River Pebble)

Clastic Sedimentary Rock (Iron-rich)

Greenstone (Rough Jadeite or Nephrite)

Sodium aluminum silicate (Jadeite) / Calcium magnesium iron silicate (Nephrite)

Lapis Lazuli

Lapis Lazuli (Complex silicate: Na8[Al6Si6O24]Sn)

Raw Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Schist

Schist (various mineral compositions)

Limonite after Marcasite (Propeller Conchoid)

Goethite/Limonite pseudomorph after Marcasite (FeO(OH)·nH2O)

Jasper

Silicon Dioxide (Microcrystalline Quartz), SiO2

Ferruginous Sandstone

Iron-rich Clastic Sedimentary Rock

Ironstone Concretion

Siderite or Hematite Concretion (FeCO3 or Fe2O3)

Limonite Concretion (Goonie or Rattlestone)

Limonite (FeO(OH)·nH2O)

Siltstone with Iron Staining

Siltstone

Jade (Nephrite or Jadeite)

Nephrite: Ca2(Mg,Fe)5Si8O22(OH)2; Jadeite: NaAlSi2O6

Khondalite

Garnet-Sillimanite-Graphite Gneiss

Limonite Pseudomorph after Pyrite

Limonite (FeO(OH)·nH2O) replacing Pyrite (FeS2)

Weathered iron-rich rock, possibly laterite or limonite-bearing sandstone

Laterite/limonite-rich material; commonly dominated by goethite (FeO(OH)) and hydrated iron oxides

Greenstone / Greenstone Pebble

Greenschist (metamorphosed basalt or gabbro)

Hematitic Sandstone

Sandstone with Hematite inclusions (SiO2 + Fe2O3)

Nephrite Jade

Ca2(Mg,Fe)5Si8O22(OH)2 (Actinolite-Tremolite series)

Ferruginous Sandstone

Arenite with Iron-Oxide cement (Fe2O3 · nH2O)

Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

Citrine (Yellow Quartz)

Silicon Dioxide (SiO2)

Anthracite Coal

Anthracite (Carbon-rich metamorphic rock)

Jadeite

NaAlSi2O6; Jadeite silicate mineral

Serpentine / Serpentinite (with Weathering Crust)

Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4

Serpentine (Serpentinite)

Hydrous magnesium iron silicate, (Mg,Fe)3Si2O5(OH)4

Greenstone (or Greywacke/Metasediment Pebble)

Metamorphosed Mafic Rock / Chlorite Schist