Chert
Silicon dioxide (SiO2)
Sedimentary
Category
Metamorphic (Low Grade)
Browse metamorphic (low grade) specimens identified by the Rock Identifier community.
Ironstone (Limonitic Sandstone)
Ferruginous Sandstone (rich in Limonite: FeO(OH)·nH2O)
sedimentary
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
mineral
Limonite (with Goethite/Ironstone)
FeO(OH)·nH2O (Hydrated Iron Oxide)
mineral
Ferruginous Sandstone (Ironstone)
Sandstone with Hematite/Goethite cement (SiO2 + FeO(OH))
sedimentary
Ironstone Concretion
Siderite or Ferruginous Concretion (FeCO3 or Iron Oxides)
sedimentary
Limonite (Hydrated Iron Oxide / Bog Iron)
FeO(OH)·nH2O
Mineral (Sedimentary context)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
metamorphic
Ferruginous Sandstone (Gozzan/Ironstone)
Arenite with Limonite/Goethite cement (FeO(OH)·nH2O)
sedimentary
Siderite Concretion (Nodule)
Iron Carbonate (FeCO3) Concretion
sedimentary
Ferruginous Sandstone
Sandstone with Iron Oxide (Limonite/Goethite)
sedimentary
Aquamarine
Beryllium aluminum silicate (Be3Al2Si6O18)
mineral
Ferruginous Sandstone (Ironstone)
Clastic sedimentary rock (SiO2 with Fe2O3/FeO(OH) cement)
sedimentary
Ironstone (Limonitic Shale)
Ferruginous Siltstone / Goethite-rich Sedimentary Rock
sedimentary
Limonite (Iron Ore)
Limonite (Hydrous ferric oxides), generic formula FeO(OH)·nH2O
mineral
Dyed Quartz Geode
Silicon Dioxide (SiO2) with artificial pigment
mineral
Anthracite Coal
Anthracite (Carbon-rich Sedimentary Rock)
sedimentary
Glauconitic Sandstone (Greensand)
Glauconitic Quartz Arenite (Formula: (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
Porcelain Tile (Sandstone-look)
Man-made Ceramic (resembling Quartz-rich Sandstone)
sedimentary (imitation)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Amygdaloidal Basalt with Epidote/Chlorite
Basalt (containing (Ca2(Al2Fe3+)(SiO4)(Si2O7)O(OH)))
igneous
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Almandine Garnet
Almandine, Fe3Al2(SiO4)3
mineral
Nephrite Jade
Ca2(Mg,Fe)5Si8O22(OH)2
metamorphic
Blue Chalcedony
Cryptocrystalline Quartz (SiO2)
mineral
Amazonite
K(AlSi3O8), Microcline (potassium feldspar)
mineral
Eclogite
Eclogite (Pyrope-Omphacite rock)
metamorphic
Sapphirine in Magnesian Schist
Sapphirine: (Mg,Al)8(Al,Si)6O20
metamorphic
Pyrite in Quartzite/Graphite Matrix
Iron Sulfide (FeS2)
Mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Arsenic (Native)
Arsenic (As)
mineral
Osumilite in Granite Matrix
(K,Na)(Fe,Mg)2(Al,Fe)3(Si,Al)12O30
mineral
Schist (Micaceous)
Mica Schist (predominantly Muscovite or Biotite)
metamorphic
Jadeite (Jade)
NaAlSi2O6 (Sodium Aluminum Silicate)
metamorphic
Pyrite
Iron Sulfide (FeS2)
mineral
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Basalt (Greenstone)
Amygdaloidal Basalt / Chloritized Basalt
Igneous
Diamond
Diamond (C)
mineral
Botryoidal Chalcedony (likely Desert Rose/Agatized Geode Crust)
Silicon Dioxide (SiO2)
mineral
Glauconitic Sandstone (Greensand)
Glauconitic Sandstone ((K, Na)(Fe3+, Al, Mg)2(Si, Al)4O10(OH)2)
sedimentary
Ironstone Concretion (Limonite/Goethite)
Ironstone (primarily FeO(OH)·nH2O)
sedimentary
Ironstone concretion / Limonitic Sandstone
Goethite/Hematite Cemented Sandstone (Hydrated Iron Oxide)
sedimentary