Ironstone Concretion (Iron-rich Mudstone)
Siderite / Geothite concretion (FeCO3 / FeO(OH))
Category
Browse mineral (native element alloy) specimens identified by the Rock Identifier community.
Ironstone Concretion (Iron-rich Mudstone)
Siderite / Geothite concretion (FeCO3 / FeO(OH))
Quartz-rich rock fragment
Microcrystalline quartz (SiO₂), possibly chalcedony or quartz-bearing breccia
Fossilized Tooth Fragment
Vertebrate Fossil (Mammalia indet.)
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Serpentinite
Serpentinite (Hydrated magnesium iron phyllosilicate)
Granite
Intrusive Igneous Rock (Mainly Quartz, Feldspar, and Mica)
Gneiss (specifically a Banded Gneiss pebble)
Gneiss (High-grade Regional Metamorphic Rock)
Magnetite-rich ironstone (probable magnetite ore)
Magnetite, Fe₃O₄, likely in a fine-grained ironstone matrix
Quartz (Rock Crystal) with minor impurities
Quartz (SiO2)
Basalt with Quartz Vein
Basalt (SiO2 vein inclusion)
Gossan (Iron Cap)
Limonitic Gossan (FeO(OH)·nH2O)
Polished orbicular granite (likely larvikite or orbicular diorite)
Quartz/feldspar-bearing granitoid with dark amphibole–biotite minerals; exact variety requires testing
Imperial Topaz
Aluminum silicate fluoride hydroxide (Al2SiO4(F,OH)2)
Moissanite
Silicon Carbide (SiC)
Tourmaline-bearing pegmatite
Quartz–feldspar pegmatite with black schorl tourmaline; minor mica likely present
Quartz Vein in Greenstone
Hydrothermal Quartz (SiO2) with Chlorite/Epidote Schist host rock
Quartz Geode with Calcite
Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3)
N/A - Non-Geological Item
Garnet in Schist (Mica Schist with Garnet Inclusion)
Garnetiferous Mica Schist (X3Al2(SiO4)3)
Kidney Stone
Nephrolithiasis (Calcium Oxalate, Hydroxyapatite, or Uric Acid)
Sandstone Pebbles
Arenite (primarily SiO2 with mineral cement)
Healer's Gold (Iron-Stained Quartz Cluster)
Silicon Dioxide with Iron Oxide Coating (SiO2)
Geode
Quartz / Chalcedony nodule
Quartz (Chalcedony/Agate nodule)
Silicon dioxide (SiO2)
Chalcedony with Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Peach Quartz
Silicon Dioxide (SiO2)
Amethyst Cluster
Silicon Dioxide (Quartz variety: Amethyst) - SiO2
Quartz Geode
Silicon dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Amethyst
Quartz (SiO2)
Wavellite with Quartz
Al3(PO4)2(OH,F)3 & SiO2
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Lake Superior Agate
SiO2 (Quartz variety chalcedony)
Quartz
Silicon Dioxide (SiO2)
Peacock Ore
Bornite (Cu5FeS4)
Quartz Pebble
Silicon Dioxide (SiO2)
Blue Quartz
Silicon Dioxide (SiO2) with inclusions
Quartz with Iron Staining
Silicon Dioxide (SiO2)
Pyrite in Quartz
Iron Sulfide (FeS2) embedded in Silicon Dioxide (SiO2)
Agate
Silicon Dioxide (Chalcedony), SiO2