Septarian Nodule
Septarian Nodule (Calcite, Aragonite, and Limestone/Claystone)
Category
Browse mineral with metamorphic or sedimentary host specimens identified by the Rock Identifier community.
Septarian Nodule
Septarian Nodule (Calcite, Aragonite, and Limestone/Claystone)
Garnet
Almandine formula: Fe3Al2(SiO4)3
Tumbled reddish-brown chalcedony, possibly carnelian
Chalcedony (microcrystalline quartz), SiO₂; red variety commonly called carnelian
Milky Quartz with inclusions
Silicon Dioxide (SiO2)
Epidote (Unakite-related)
Epidote (Ca2(Al,Fe)3(SiO4)3(OH))
Quartz with Epidote / Chlorite Inclusions
Silicon Dioxide (SiO2) with Epidote Ca2(Al,Fe)3(SiO4)3(OH)
Black Sapphire (Basaltic Blue Sapphire)
Corundum (Al2O3)
Weathered serpentinite (likely)
Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with possible magnetite, carbonate, and chromite
Quartz Geode / Druzy Quartz
Silicon Dioxide (SiO2)
Limestone (Travertine/Tufa variant)
Calcium Carbonate (CaCO3)
Veined quartz-bearing metamorphic rock
Likely quartzite or siliceous schist with iron-oxide staining
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Quartz Geode or Druzy Quartz on Matrix
Silicon Dioxide (SiO2)
Quartz Vein / Milky Quartz
Silicon Dioxide (SiO2)
Rose quartz
Quartz (silicon dioxide, SiO₂), pink variety
Bronzite
Enstatite (magnesium iron silicate), (Mg,Fe2+)SiO3
Iron-stained Quartz
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Prasiolite
Silicon Dioxide (SiO2)
Star Sapphire
Corundum (Al2O3) with Rutile inclusions
Black Tourmaline (Schorl)
Schorl (Sodium iron silicate hydroxide boron silicate); NaFe3Al6(BO3)3Si6O18(OH)4
Serpentinite
Serpentinite (Hydrated magnesium iron phyllosilicate)
Dendritic Agate or Manganese Nodule in Chert/Limestone
Silicon Dioxide (SiO2) with Manganese Oxide (MnO2) inclusions
Quartz with Chalcopyrite (or Pyrite)
Silicon Dioxide (SiO2) with Copper Iron Sulfide (CuFeS2)
Blue Apatite
Apatite group (Ca5(PO4)3(F,Cl,OH))
Blue Sapphire (Tumbled/Polished)
Corundum (Al2O3)
Quartz Vein in Siltstone
SiO2 (Quartz) on clastic sedimentary matrix
Fuchsite Gneiss or Schist
Muscovite (variety Fuchsite) within Metamorphic Host Rock
Charoite
Charoite (Hydrated potassium sodium calcium barium strontium silicate hydroxyfluoride)
Quartz (Druzy)
Silicon Dioxide (SiO2)
Manganese Oxide Crust on Limestone
Manganese Oxides (e.g., Pyrolusite MnO2 or Romanechite) on CaCO3
Geode or Concretion
Silica-based Concretion / Quartz Geode
Prase Quartz on Feldspar
Quartz (Silicon Dioxide, SiO2) with Hedenbergite inclusions on Potassium Feldspar (KAlSi3O8)
Turquoise (set in silver jewelry)
Turquoise - CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminum phosphate)
Fluorite Geode
Calcium Fluoride (CaF2)
Milky Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
Turquoise
Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O
Quartz-Veined Sandstone
Quartz-veined Arenite
Greenstone or Chlorite Schist
Greenschist / Chlorite schist
Amethyst and Agate Geode Section
Silicon Dioxide (SiO2) - Crystalline Quartz and Chalcedony
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Milky quartz
Quartz (SiO₂), likely massive milky quartz with minor iron-oxide staining and inclusions