Limonite (Iron Ore / Ochre)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
mineral
Category
Mineral Pseudomorph
Browse mineral pseudomorph specimens identified by the Rock Identifier community.
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Fluorite
Calcium Fluoride (CaF2)
mineral
Biotite gneiss (probable)
Foliated quartz–feldspar–mica gneiss; commonly containing biotite mica, quartz, and plagioclase/alkali feldspar
metamorphic
Copper Ore
Mixed copper sulfides/oxides in gangue matrix
mineral
Gravel and Pebbles
Unconsolidated rock fragments / detrital sediment
sedimentary
Fossilized Shark Tooth
Chondrichthyes (Class)
fossil
Fossil Shark Tooth
Carcharodon or Carcharias fossil (Vertebrate Fossil)
sedimentary
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Weathered granite or granitic gneiss
Granite/granitic gneiss, composed mainly of quartz, feldspar, and mica
igneous
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
mineral
Likely amphibolite
Amphibolite, composed mainly of hornblende and plagioclase feldspar
metamorphic
Granite
Coarse-grained felsic intrusive igneous rock, chiefly quartz, potassium feldspar, plagioclase, and biotite/hornblende
igneous
Granite (likely weathered granite or granitic gneiss)
Granite; chiefly quartz (SiO₂), feldspar, and mica
igneous
Spinosaurus fossil (permineralized bone)
Spinosaurus aegyptiacus (Calcium phosphate mineralized with silica/sediment)
sedimentary
Vesicular Basalt
Amygdaloidal Basalt (Mafic extrusive volcanic rock)
Igneous
Gneiss
Gneiss
metamorphic
Epidote
Calcium aluminum iron silicate (Ca2(Al, Fe)3(SiO4)3(OH))
mineral
Basalt with Vesicular/Amygdaloidal Alteration
Extrusive Igneous Rock (Mafic)
igneous
Basalt with Amygdule
Aphanitic Mafic Volcanic Rock (Basalt) with Zeolite/Quartz Infill
igneous
Epidote
Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
mineral
Mica schist
Schist dominated by muscovite/biotite mica, commonly with quartz and feldspar
metamorphic
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
mineral
Limonite
FeO(OH)·nH2O
mineral
Selenite (variety of Gypsum)
Calcium sulfate dihydrate (CaSO4·2H2O)
mineral
Red Sandstone (Iron-stained)
Clastic sedimentary rock (primarily Quartz with Iron Oxides)
sedimentary
Turquoise
Hydrated phosphate of copper and aluminium - CuAl6(PO4)4(OH)8·4H2O
mineral
Blue Apatite
Fluoroapatite (Ca5(PO4)3F)
mineral
Granite
Intrusive Felsic Igneous Rock
igneous
Banded Gneiss
Gneiss
metamorphic
Gravel
Unconsolidated rock fragments / detrital sediment
sedimentary
Granite
Intrusive Igneous Rock (Felsic)
igneous
Basalt with Vesicular Amygdule
Extrusive igneous rock (Mafic)
igneous
Sandstone with Quartz/Calcite druse
Arenite with druse (SiO2 or CaCO3)
sedimentary
Hag Stone
Perforated sedimentary rock (typically sandstone or limestone)
sedimentary
Granite
Intrusive igneous rock
igneous
Fossil / Permineralized Bone
Tyrannosaurus rex fossil (Hydroxylapatite replaced by various minerals)
sedimentary
Yellow Apatite
Fluorapatite (Ca5(PO4)3(F,Cl,OH))
mineral
Limonite
FeO(OH)·nH2O
mineral
Banded Sandstone (River Cobble)
Arenite Sandstone with heavy mineral layering
sedimentary
Small pale mineral fragment, possibly calcite
Unidentified; calcite (CaCO₃) is one possibility
mineral
Hematite (likely Botryoidal or Specularite variant)
Iron(III) oxide (Fe2O3)
mineral
Hematite
Iron(III) oxide (Fe2O3)
mineral