Banded gneiss pebble
Gneiss, likely quartz–feldspar–mica gneiss
Category
Browse mineral (man modified) specimens identified by the Rock Identifier community.
Banded gneiss pebble
Gneiss, likely quartz–feldspar–mica gneiss
Limonite (Ironstone)
Hydrated Iron(III) Oxide-hydroxide (FeO(OH)·nH2O)
Obsidian (Black)
Obsidian (High-silica volcanic glass)
Quartz (Quartzite)
Silicon Dioxide (SiO2)
Limonite and Goethite (Ironstone)
Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)
Iron-stained quartz-rich rock, possibly goethite-bearing quartz
Quartz (SiO₂) with iron oxides/hydroxides, likely goethite or limonite
Calcite (commonly referred to as Orange Calcite or Honey Calcite given its color)
Calcite
Greywacke (likely)
Greywacke (a type of sandstone)
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Bioclasts
Milky Quartz
Silicon Dioxide (SiO2)
Tumbled serpentine
Serpentinite; chiefly antigorite, lizardite, and/or chrysotile [Mg₃Si₂O₅(OH)₄]
Tumbled black-and-white stone, likely dendritic agate or jasper
Cryptocrystalline quartz (SiO₂), possibly chalcedony with manganese-oxide dendrites
Milky quartz
Quartz, silicon dioxide (SiO₂)
Fluorite
Calcium Fluoride (CaF2)
Fluorite
Calcium Fluoride (CaF2)
Specular Hematite with Quartz
Ferric oxide (Fe2O3) and Silicon dioxide (SiO2)
Fluorite
Fluorite (Calcium Fluoride, CaF2)
Fluorite (Rainbow Fluorite)
Calcium Fluoride (CaF2)
Gold Nugget
Native Gold (Au)
Fluorite (often called Rainbow Fluorite or Purple-Green Fluorite)
Calcium Fluoride (CaF2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Iron-rich Gossan with Quartz
Limonite and Goethite with Silicon Dioxide (SiO2)
Weathered green-gray stone, likely serpentinite or chlorite-rich metamorphic rock
Probable serpentinite (antigorite–lizardite), possibly chlorite schist or altered basalt
Serpentinite
Serpentinite; chiefly serpentine-group minerals (lizardite, chrysotile, antigorite), commonly with magnetite and minor talc
Milky quartz with iron-oxide staining
Quartz (silicon dioxide, SiO₂)
Chalcedony on Matrix
Silicon Dioxide (SiO2)
Polished dendritic jasper or agate slab
Microcrystalline quartz (SiO₂), likely jasper with chalcedony and iron/manganese dendrites
Amygdaloidal Basalt
Amygdaloidal Basalt (Ca-rich Plagioclase, Pyroxene, and Olivine)
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Green Fluorite (Fluorite Sphere)
Calcium Fluoride (CaF2)
White Quartz
Silicon Dioxide (SiO2)
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Tumbled serpentine with dark magnetite/chromite matrix
Serpentinite; chiefly antigorite/lizardite, Mg3Si2O5(OH)4, with magnetite and possibly chromite
Mica-rich schist
Muscovite–biotite schist, commonly quartz-bearing
White Marble
Recrystallized Calcite (CaCO3)
Greenstone
Greenschist (metamorphosed mafic igneous rock)
Granitic Gneiss
Gneiss (Polymetamorphic Granitic Gneiss)
Olivine (Peridot in gem form)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Emerald crystal in host rock
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
Gneiss pebble
Banded gneiss, commonly quartz–feldspar–biotite gneiss
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Banded sandstone pebble
Lithified quartz–feldspar sandstone, likely ferruginous and carbonaceous laminae