Pegmatite
Pegmatite (felsic intrusive igneous rock)
Category
Browse mineral composite specimens identified by the Rock Identifier community.
Pegmatite
Pegmatite (felsic intrusive igneous rock)
Greenstone / Epidosite
Epidosite (primary minerals: Epidote and Quartz)
Green Jasper
Silicon Dioxide (SiO2) with mineral inclusions
Fluorite on Matrix
Calcium Fluoride (CaF2)
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)
Copper Ore (Malachite, Azurite, and Chalcopyrite in Host Rock)
Copper-bearing polymetallic mineral aggregate (Cu-minerals)
Rock Specimen
Unclassified rock specimen
Quartz-rich pegmatite (likely feldspar–quartz rock)
Granitic pegmatite; predominantly quartz (SiO₂) and feldspar, with possible mica and iron-oxide staining
Sandstone
Arenite (SiO2 principal composition)
K-Feldspar (Potassium Feldspar / Pink Feldspar)
KAlSi3O8 (Potassium Aluminum Silicate)
Petrified Wood / Fossilized Wood
Silicified Wood (Silicon Dioxide - SiO2)
Sandstone
Clastic Sedimentary Rock
Amygdaloidal Basalt with Agate/Zeolite Amygdules
Basalt (extrusive igneous rock) containing secondary mineral fillings
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)
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))
Limonite (Iron Ore)
FeO(OH)·nH2O
Black Sand (Magnetite Sand)
Magnetite (Fe3O4)
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
Banded Gneiss
Gneiss (typically quartz, feldspar, mica, amphibole composition)
Quartz geode
Microcrystalline and crystalline quartz (SiO₂), likely chalcedony-lined geode
Likely fluorite fragments
Fluorite (calcium fluoride, CaF₂)
Red Sandstone
Arenite (primarily Quartz with Iron Oxide coating)