Schist
Schist (various mineral compositions)
Category
Browse igneous and metamorphic derivative (weathered) specimens identified by the Rock Identifier community.
Schist
Schist (various mineral compositions)
Sandstone (likely Graywacke or Lithic Sandstone)
Arenite / Wacke (SiO2 based with lithic fragments)
Milky Quartz Pebble (Tumbled Quartzite)
Silicon Dioxide (SiO2)
Schist
Schist (various compositions)
Quartz on Greenstone
Silicon Dioxide (SiO2) on Altered Igneous Geologic Unit
Limonite (Iron Stone/Ocher)
Limonite (FeO(OH)·nH2O)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Grey Agate (Banded Chalcedony)
Agate (Silicon Dioxide - SiO2)
Milky Quartz
Quartz (Silica / Silicon Dioxide), SiO2
Milky Quartz
Quartz (Silica / Silicon Dioxide, SiO2)
Quartz crystal with Pyrite inclusions
Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)
Clear Quartz (Tumbled)
Quartz (Silicon Dioxide - SiO2)
Pyrite
Iron Disulfide (FeS2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Citrine Geode Fragment
Citrine (Silicon Dioxide with Iron Impurities), SiO2
Yellow Quartz (Citrine Quartz Pebble)
Silicon Dioxide (SiO2)
Quartz (specifically Milky/Gray Quartz)
Silicon Dioxide (SiO2)
Gneiss
Gneiss
Milky Quartz with Country Rock contact
Silicon Dioxide (SiO2) in contact with Metamorphic/Igneous rock
Smoky Quartz
Smoky Quartz (SiO2)
Baroque Pearl (and potentially a small Sapphire/Blue Topaz)
Pearl: Calcium Carbonate (aragonite or calcite) with conchiolin. Sapphire: Aluminum Oxide (Al2O3). Blue Topaz: Al2SiO4(F,OH)2.
Green Aventurine and Clear Quartz
Green Aventurine (Silicon Dioxide - SiO2 with Fuchsite inclusions); Clear Quartz (Silicon Dioxide - SiO2)
Muscovite Mica
Muscovite - KAl2(AlSi3O10)(OH)2
Mica (Muscovite)
Muscovite, KAl2(AlSi3O10)(OH)2
Agate
Agate (a cryptocrystalline variety of Quartz, SiO₂)
Almandine Garnet
Iron aluminum silicate (Fe3Al2(SiO4)3)
Weathered Sandstone with Algae Growth
Arenite
Serpentine Jade (New Jade/Olive Jade)
Serpentinite (a rock composed primarily of serpentine minerals) / Mg3Si2O5(OH)4 for Antigorite and Lizardite
Labradorite (tumbled)
Labradorite (a plagioclase feldspar mineral between anorthite and albite; chemical formula: (Ca,Na)(Si,Al)4O8)
Ruby
Corundum (Al2O3 with Chromium traces)
Citrine Quartz Crystal Cluster
Silicon Dioxide (SiO2) with iron impurities
Sodalite
Na8(Al6Si6O24)Cl2 (Sodalite)
Ruby
Corundum (Al2O3:Cr)
Ruby
Corundum (Aluminum Oxide with Chromium traces), Al2O3:Cr
Milky Quartz
Silicon Dioxide (SiO2)
Water and Silt (Sedimentary Environment)
Suspended Sediment / H2O (dihydrogen monoxide)
Milky Quartz
Silicon Dioxide (SiO2)
Bull Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Amethyst (Chevron or Banded Amethyst)
Silicon Dioxide (SiO2) with iron impurities
Red Garnet
Pyrope-Almandine series (Mg3Al2(SiO4)3 to Fe3Al2(SiO4)3)