Dark polished stone, likely basalt or slag-like volcanic rock
Probable fine-grained basalt; exact identification requires testing
Category
Browse mineral like byproduct specimens identified by the Rock Identifier community.
Dark polished stone, likely basalt or slag-like volcanic rock
Probable fine-grained basalt; exact identification requires testing
Likely slag or metallic industrial byproduct
Unidentified iron-rich ferrous slag; possibly magnetite-bearing slag
Carborundum (Silicon Carbide)
Silicon Carbide (SiC)
Gneiss or Schist
Gneiss or Mica Schist with Garnet
Unopened Geode
Geode (containing various mineralization like Quartz SiO2)
Fluorite
Calcium fluoride (CaF2)
Bauxite
Bauxite (Al2O3·2H2O mixed with iron oxides)
Blue slag-like mineral specimen, possibly bornite or chalcopyrite
Tentatively bornite (Cu5FeS4) or iridescent chalcopyrite (CuFeS2)
Pegmatite
Pegmatite (felsic intrusive igneous rock)
Snowflake Obsidian
Volcanic Glass with Spherulite inclusions (mainly Cristobalite)
Pink Feldspar (Orthoclase)
Orthoclase Feldspar (KAlSi3O8)
Raw Fluorite
Calcium Fluoride (CaF2)
Garnet
Pyrope or Almandine (X3Y2(SiO4)3)
Gneiss
Gneiss
Green Fluorite
Calcium Fluoride (CaF2)
Gneiss (Banded Gneiss)
Gneiss
Pegmatite
Igneous Pegmatite
Granitic Pegmatite with Schorl Tourmaline
Granitic Pegmatite (Schorl: NaFe3Al6(BO3)3Si6O18(OH)4)
Bauxite (Aluminum Ore)
Hydrated aluminum oxides, primarily Al(OH)3, AlO(OH)
Picture Jasper
Silicified microcrystalline quartz, SiO2
Vein Quartz in Basalt
Silicate-veined volcanic rock
Gneiss
Gneiss
Muscovite Mica
Muscovite (Potassium Aluminum Silicate) - KAl2(AlSi3O10)(F,OH)2
Moss agate (likely plume or dendritic agate)
Chalcedony, microcrystalline quartz (SiO₂), with iron-oxide inclusions
Sandstone
Clastic Sedimentary Rock
Kimberlite
Ultramafic igneous rock
Gneiss
Metamorphic Gneiss (High-grade regional metamorphism)
Green Garden Quartz (Phantom Quartz)
Silicon Dioxide (SiO2) with Chlorite inclusions
Quartz Geode
Silicon Dioxide (SiO2)
Blue goldstone (man-made glass)
Copper-bearing aventurine glass; synthetic silicate glass
Sandstone
Arenite
Ruby
Corundum (Aluminium Oxide with Chromium impurities, Al2O3:Cr)
Sandstone
Arenite (SiO2 based typically)
Granitic Pegmatite
Pegmatitic Granite
Blue Aventurine
Quartzite with inclusions of Dumortierite (SiO2 + Al7(BO3)(SiO4)3O3)
Sunstone (Feldspar)
(Ca,Na)((Al,Si)2Si2O8) with inclusions of Hematite or Goethite
Dendritic Agate
Silicon Dioxide (Chalcedony with manganese or iron oxide inclusions)
Pegmatite (Granitic)
Granite Pegmatite
Plume Agate or Moss Agate
Agate (SiO2)
Sandstone
Arenite (SiO2 based)
Gneiss
Gneiss
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite mica