Limonite
FeO(OH)•nH2O
mineral
Category
Minerals
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Limonite
FeO(OH)•nH2O
mineral
Limonite
FeO(OH)•nH2O
mineral
Schist
Schist
metamorphic
Fossil Shark Tooth
Odontaspididae (Sand Tiger Shark family)
fossil
Pink Granite
Granite (Phaneritic Quartz-Feldspar rock)
igneous
Gneiss
Gneiss (Metamorphic Rock)
metamorphic
Diorite
Phaneritic Intermediate Igneous Rock
igneous
Granite
Granite (Felsic Plutonic Rock)
igneous
Weathered, quartz-rich metamorphic rock (likely schist or gneiss)
Quartz–feldspar–mica schist/gneiss, with surface lichens and iron-oxide staining
metamorphic
Granite Gneiss
Gneiss (Derived from Granite protolith)
metamorphic
Nickel coin (U.S. currency)
Cupronickel (75% Copper, 25% Nickel alloy)
man-made alloy (metallic)
Likely pegmatite with quartz and mica
Granitic pegmatite, chiefly quartz (SiO₂), feldspar, and mica
igneous
Quartz-rich hydrothermal mineral specimen, possibly vanadinite-bearing matrix
Quartz (SiO₂) with unidentified red-brown accessory minerals; exact species requires testing
mineral
Possibly turquoise or chrysocolla
Indeterminate copper-bearing mineral; turquoise is CuAl₆(PO₄)₄(OH)₈·4H₂O, while chrysocolla is a variable hydrated copper silicate
mineral
Quartz Mineral
Silicon Dioxide (SiO2)
mineral
Possible mafic xenolith in granite
Dark mafic inclusion, likely amphibolite or gabbro, enclosed in coarse-grained granite
igneous
Granite boulder
Granite, a coarse-grained felsic intrusive igneous rock composed mainly of quartz, feldspar, and mica
igneous
Gneiss
Gneiss
metamorphic
Likely weathered granite or granitic gneiss
Quartz–feldspar–mica rock; possibly gneissic granite
igneous
Pegmatite
Pegmatite (felsic intrusive igneous rock)
igneous
Quartz with Mineral Inclusions
Silicon Dioxide (SiO2)
mineral
Serpentine (rough serpentine-rich rock)
Serpentine-group minerals, chiefly antigorite and/or lizardite; composition broadly Mg₃Si₂O₅(OH)₄
metamorphic
Milky quartz
Quartz, silicon dioxide (SiO₂)
mineral
Weathered serpentinized ultramafic rock
Serpentinite; chiefly serpentine-group minerals, commonly with magnetite, brucite, talc, and relict olivine/pyroxene
metamorphic
Quartz–calcite sulfide-bearing mineral specimen
Quartz (SiO₂) with likely calcite (CaCO₃) and iron sulfides, possibly pyrite (FeS₂); exact species requires testing
mineral
Schist
Schist; commonly mica schist, composed chiefly of muscovite/biotite mica with quartz and feldspar
metamorphic
Azurite and Malachite
Cu3(CO3)2(OH)2 (Azurite) and Cu2(CO3)(OH)2 (Malachite)
mineral
Ferruginous Sandstone (Gozzanous)
SiO2 (Quartz) with FeO(OH) (Goethite) or Fe2O3 (Hematite) coating
sedimentary
Schist
Mica Schist
metamorphic
Limonite Concretion
Limonite (Hydrated Iron Oxide) FeO(OH)·nH2O
sedimentary
Shark Tooth Fossil
Vertebrate fossilized tooth
fossil
Weathered dark volcanic rock, possibly basalt
Basalt (tentative; likely iron-rich mafic volcanic rock)
igneous
Pink granite pebble
Granite, a coarse-grained felsic intrusive igneous rock
igneous
Mica Schist
Schist (primarily Muscovite and Biotite mica)
metamorphic
Dark mafic rock, likely basalt
Basalt; chiefly plagioclase feldspar and pyroxene, commonly with minor olivine and magnetite
igneous
Limonite
FeO(OH)•nH2O
mineral
Limonite
FeO(OH)•nH2O
mineral
Limonite
FeO(OH)•nH2O
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Marble
Recrystallized Calcite (CaCO3)
metamorphic
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary