Limonite
FeO(OH)•nH2O
Category
Browse mineral (evaporite) 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]
Quartz crystal cluster in matrix
Silicon dioxide (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)
Gneiss
Metamorphic Foliated Gneiss
Quartz geode
Microcrystalline and crystalline quartz (SiO₂), likely chalcedony-lined geode
Vesicular basalt pebble
Basalt, a mafic volcanic rock composed mainly of plagioclase feldspar, pyroxene, and often olivine
Pegmatitic granite
Coarse-grained granite/pegmatite, chiefly quartz, feldspar, and mica
Likely fluorite fragments
Fluorite (calcium fluoride, CaF₂)
Banded Gneiss Pebble
Gneiss (Metamorphic Rock)
Quartz-rich gneiss (probable banded metamorphic rock)
Gneiss; composition chiefly quartz, feldspar, and mica, possibly with amphibole
Epidote
Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
Epidote
{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Epidote
Epidote (Ca2(Al,Fe)3(SiO4)3(OH))
Epidote
Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
Milky quartz fragment
Quartz, silicon dioxide (SiO₂)
Blue Apatite
Apatite (Ca5(PO4)3(F,Cl,OH))
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Fluorite
Calcium fluoride (CaF2)
Malachite and Azurite on Gossan (Ironstone Matrix)
Cu2CO3(OH)2 (Malachite) on FeO(OH)·nH2O (Limonite/Gossan)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Weathered vesicular volcanic rock (likely basalt or andesite)
Amygdaloidal basalt/andesite; cavities may contain calcite, zeolites, or silica minerals
Tumbled or weathered gneiss
Feldspar–quartz–mica gneiss (composition variable)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Extrusive volcanic rock)
Snowflake Obsidian
Obsidian with Cristobalite inclusions
Sandstone Pebble with Mineral Encrustation
Quartz Sandstone with Calcite/Halite Crust
Blue Apatite
Calcium phosphate mineral, Ca5(PO4)3(F,Cl,OH)
Limonite / Ironstone
Hydrated Iron Oxide (FeO(OH)·nH2O)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Polished copper-bearing mineral specimen, likely malachite-rich copper ore
Malachite, Cu₂CO₃(OH)₂, possibly mixed with chrysocolla or limonite
Tiger's Eye
Silicon Dioxide (SiO2) with fibrous inclusions
Fossilized bone fragment (probable mammalian tooth or bone)
Mineralized bone, commonly hydroxyapatite [Ca5(PO4)3(OH)] replaced or impregnated by silica/calcite
Fossilized Shark Tooth
Chondrichthyes (Class)
Gneiss
Gneiss
Schist
Schist; commonly mica schist, composed chiefly of muscovite/biotite mica with quartz and feldspar
Greenstone / Metabasalt
Chlorite schist or Epidiorite
Greenstone
Protolith: Basaltic rock