Biotite (Black Mica)
Biotite (K(Mg,Fe)3AlSi3O10(OH)2)
Category
Browse mineral based composite specimens identified by the Rock Identifier community.
Biotite (Black Mica)
Biotite (K(Mg,Fe)3AlSi3O10(OH)2)
Corundum (Sapphire/Ruby in Matrix)
Aluminium oxide (Al2O3)
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
Muscovite Mica
Muscovite - KAl2(AlSi3O10)(OH)2
Bismuth Crystal
Bismuth (Bi)
Celestite (Celestine)
Celestine (Strontium Sulfate, SrSO4)
Limestone
Calcium Carbonate (CaCO3)
Sandstone (Iron-stained)
Clastic sedimentary rock (SiO2 with Fe2O3 staining)
Shale (Beach-worn)
Laminated Pelite (primarily clay minerals and quartz)
Goldstone (Synthetic Aventurescence Glass)
Cuprous Aventurescent Glass (Silicon Dioxide with Copper inclusions)
Granite
Granite (Felsic Plutonic Rock)
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
Citrine (likely Heat-Treated)
Quartz (Silicon Dioxide, SiO2)
Granite
Phaneritic Felsic Igneous Rock
Basalt with Scoria/Vesicular Texture
Vesicular Basalt (Iron-rich/Oxidized)
Copper-bearing Mica Schist
Mica Schist with Native Copper inclusions
Quartz Crystal (specifically a Double-Terminated variety)
Silicon Dioxide (SiO2) - Low Quartz
Granite
Granite (composed primarily of Quartz SiO2, Potassium Feldspar KAlSi3O8, and Plagioclase)
Granite
Phaneritic Felsic Igneous Rock
Garnet-Bearing Schist
Almandine Garnet Micaceous Schist
Mahogany Obsidian
Volcanic Glass with Hematite inclusions (SiO2 + Fe2O3)
Conglomerate
Conglomerate (clastic sedimentary rock)
Sandstone (Ferruginous)
Arenite with Iron Oxide cement
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
Mica (Biotite or Phlogopite variety)
Phyllosilicate (complex mineral formula involving K, Mg, Fe, Al, Si, and O)
Basalt with Iron Oxidation
Mafic Igneous Rock (Basalt)
Mica Schist
Mica Schist (Complex Silicate Rock)
Biotite Schist
Biotite Schist (Rich in K(Mg,Fe)3AlSi3O10(OH)2)
Quartz with Mica (Gneissic or Pegmatitic origin)
Silicon Dioxide (SiO2) with Phyllosilicates (KAl2(AlSi3O10)(F,OH)2)
Basalt
Extrusive mafic igneous rock
Vesicular Basalt (or Scoria)
Vesicular Basalt (Aphanitic-vesicular volcanic rock)
Basalt with Epidote Veins
Mafic Igneous Rock (Basalt)
Garnet Schist
Almandine Garnet-Mica Schist (X₃Y₂(SiO₄)₃)
Picasso Stone
Metamorphosed Calcium Carbonate (Limestone)
Granite
Phaneritic Felsic Igneous Rock
Porphyritic Basalt (with Amygdales)
Amygdaloidal Porphyritic Basalt
Milky Quartz
Silicon Dioxide (SiO2)
Granite
Phaneritic plutonic rock (composed mainly of SiO2, Al2O3, K2O, and Na2O)
Sandstone (Quartzose Pebble)
Clastic sedimentary rock (primarily SiO2)
Diorite (Salt and Pepper Rock)
Diorite