Geode
Quartz / Chalcedony nodule
Category
Browse mineral pseudomorph specimens identified by the Rock Identifier community.
Geode
Quartz / Chalcedony nodule
Vanadinite
Vanadinite (Pb5(VO4)3Cl)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrated copper aluminum phosphate)
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2) with Hematite/Limonite
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Turquoise or Chrysocolla (Inlaid Jewelry)
Hydrated copper aluminum phosphate / Hydrated copper phyllosilicate
Ironstone (likely Limonite or Goethite nodule)
Hydrothermally altered Ferric Hydroxide (FeO(OH)·nH2O)
Limonite with Hematite
Limonite (FeO(OH)·nH2O) and Hematite (Fe2O3)
Ironstone Concretions (Ironstone)
Ferruginous Sandstone or Siltstone (Fe2O3)
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
Limonite (Gossan)
FeO(OH)·nH2O (Hydrated Iron Oxide)
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
Malachite
Copper carbonate hydroxide [Cu2CO3(OH)2]
Turquoise
Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O
Green Moonstone (Garnierite)
Nickel-bearing Magnesium Silicate (often a mix of Serpentine and Talc/Chlorite groups)
Pyrite in Matrix
Iron Sulfide (FeS2)
Fossilized Shark Tooth
Carcharodon (Galeocerdo sp. or Lamniform)
Kidney Stone
Nephrolith (typically Calcium Oxalate - CaC2O4)
Snowflake Obsidian
Volcanic Glass (SiO2 rich with Cristobalite inclusions)
Chrysocolla
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O)
Sandstone
Arenite (SiO2 primarily)
Limonite (Ironstone)
FeO(OH)qn H2O
Pyrite
Iron Sulfide (FeS2)
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Sandstone
Arenite (SiO2 principal)
Schist
N/A (a rock type, not a mineral formula)
Small polished dark mineral or gemstone fragment
Indeterminate; possibly smoky quartz, obsidian, or dark tourmaline
Tumbled or cut iron-rich mineral specimen
Likely limonite/goethite (hydrated iron oxides), possibly weathered hematite
Blue-green copper mineral specimen, likely chrysocolla-bearing rock
Chrysocolla, hydrated copper phyllosilicate: approximately (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O; possibly mixed with malachite or chrysocolla matrix
Tumbled pale green mineral specimen, likely calcite
Calcite (CaCO₃), tentative identification
Tumbled blue glassy mineral, possibly sodalite or blue aventurine
Identification uncertain; likely sodalite (Na₈Al₆Si₆O₂₄Cl₂) or blue-dyed quartz/slag-like material
Polished brown mineral fragment, likely quartz-rich iron-stained material
Possibly quartz (SiO₂) with iron-oxide inclusions; exact identification is uncertain from the image
Likely quartz-bearing mineral aggregate
Quartz (SiO₂), possibly mixed with mica or feldspar
Carved Gemstone Mushroom
Quartz / Feldspar composite (Carved lapidary art)
Tumbled purple jasper (likely)
Microcrystalline quartz/chalcedony, SiO₂, colored by iron and other trace minerals
Raw Garnet Fragment
Nesosilicate Group (e.g., Almandine, Fe3Al2(SiO4)3)
Limonite (Limonitic Sandstone)
Hydrated Iron(III) Oxide-Hydroxide ($FeO(OH)·nH_2O$)
Limonite (Iron-rich Gossan/Laterite)
FeO(OH)·nH2O (Hydrated Iron Oxide)
Mixed Crushed Stone
Aggregate (varied mineral composition)
Fossil shark teeth
Likely fossilized shark teeth, possibly Carcharhiniformes or related sharks; exact species cannot be determined from the photo.
Copper Ore (Malachite/Chrysocolla bearing)
Cupriferous rock containing secondary copper minerals like Cu2CO3(OH)2
Gossan (with Limonite/Hematite coating)
Ferruginous Gossan (Fe2O3·nH2O / Fe2O3)