Limonite
FeO(OH)•nH2O
Category
Browse mineral (extraterrestrial) specimens identified by the Rock Identifier community.
Limonite
FeO(OH)•nH2O
Chrysocolla
Hydrated copper phyllosilicate, (Cu,Al)2H2Si2O5(OH)4·nH2O
Malachite
Copper carbonate hydroxide [Cu2CO3(OH)2]
Milky Quartz with Algae/Chlorite
Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2 based)
Limonite (Ironstone)
Limonite (FeOO·nH2O)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Sandstone (with Concretion)
Arenite / Quartzose Sandstone
Pyrite (on host rock)
Iron Sulfide (FeS2)
Yellow Calcite
Calcium Carbonate (CaCO3)
Limonite (Ironstone)
Goethite/Limonite (Hydrated iron(III) oxide-hydroxide)
Selenite (Satin Spar)
Gypsum (CaSO4·2H2O)
Turquoise (Dyed Howlite/Magnesite imitation)
CuAl6(PO4)4(OH)8·4H2O (Target mineral) / Ca2B5SiO9(OH)5 (Actual specimen: Howlite)
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Vesicular basalt
Basalt, commonly plagioclase feldspar + pyroxene ± olivine
Azurite Malachite (Mixed)
Azurite-Malachite; Azurite: Cu3(CO3)2(OH)2 / Malachite: Cu2CO3(OH)2
Quartz (Druzy)
Silicon Dioxide (SiO2)
Ruby (Raw Corundum)
Corundum (Al2O3) with Chromium traces
Granite
Granite (felsic intrusive igneous rock)
Likely serpentinite (green serpentine rock)
Serpentinite, composed chiefly of serpentine-group minerals (antigorite, lizardite, and/or chrysotile)
Limonite with Quartz
Hydrated Iron Oxide Hydroxide, FeO(OH)·nH₂O with SiO₂
Pegmatite
Pegmatite (felsic intrusive igneous rock)
Quartz in Greenstone
Metamorphic rock with quartz vein (SiO2 / mixed silicates)
Quartz crystal cluster in matrix
Silicon dioxide (SiO2)
Alabaster
Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)
Jasper Mushroom Carving
Silicon Dioxide (Microcrystalline Quartz, SiO2)
Copper Ore (Malachite and Limonite bearing)
Cuprite, Malachite, and Limonite mixture
Banded Iron Formation (Fragment)
Banded Iron Formation (BIF)
Calcite (Honey Calcite and Agate)
Calcium Carbonate (CaCO3)
Yellow Quartz
Silicon Dioxide (SiO2)
K-Feldspar (Potassium Feldspar / Pink Feldspar)
KAlSi3O8 (Potassium Aluminum Silicate)
Weathered rock with a tan mineral vein or inclusion
Indeterminate from the photograph; possibly a quartz- or feldspar-rich vein in dark metamorphic host rock
Quartz-rich granite pebble
Granite, composed mainly of quartz, feldspar, and mica
Small banded metamorphic rock fragment
Indeterminate foliated metamorphic rock; possibly mica schist or gneiss
Fossil shark tooth, likely sand tiger shark
Fossilized selachian tooth; possibly *Carcharias* or *Striatolamia*
Shark Tooth Fossil
Carcharodon / Otodus fossilized tooth (Calcium Phosphate / Hydroxyapatite)
Fossilized Shark Tooth
Chondrichthyes (Class)
Small tan mineral or rock fragment (unidentified)
Indeterminate from the image; no diagnostic features are visible
Small amber-colored mineral fragment (identity uncertain)
Undetermined; appearance alone is insufficient for a reliable mineral identification
Small cylindrical mineral/stone fragment
Undetermined; the image is insufficient for reliable mineral identification
Pegmatite (Feldspar and Quartz)
Pegmatite (KAlSi3O8 / SiO2)
Fluorite
Calcium Fluoride (CaF2)