Citrine
SiO2 (Silicon Dioxide)
Category
Browse mineral like biological tissue specimens identified by the Rock Identifier community.
Citrine
SiO2 (Silicon Dioxide)
Obsidian
Obsidian (Volcanic Glass, primarily SiO2)
Green Fluorite
Calcium Fluoride (CaF2)
Sandstone (Wonderstone)
Silicified Sandstone / Orthoquartzite with Liesegang rings
Shale
Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)
Botryoidal Chalcedony (Druzy Quartz)
Silicon Dioxide (SiO2)
Kyanite in Quartz
Kyanite (Al2SiO5) with Quartz (SiO2)
Limonite / Ironstone Nodule
Limonite (Hydrated iron(III) oxide-hydroxide), FeO(OH)·nH2O
Basalt (Greenstone)
Amygdaloidal Basalt / Chloritized Basalt
Dendritic Opal
Hydrated Silica with Manganese inclusions (SiO2·nH2O)
Gneiss
Gneiss
Snowflake Obsidian
Hydrated Volcanic Glass (primarily SiO2) with Cristobalite inclusions
Fluorite
Fluorite (Calcium Fluoride, CaF2)
Potassium Feldspar
Orthoclase (KAlSi3O8)
Granite
Granite (Felsic Plutonic Rock)
Obsidian (Gold Sheen)
Obsidian (SiO2 + impurities)
Serpentinite
Serpentinite (composed primarily of serpentine minerals like antigorite, chrysotile, and lizardite)
Quartz Vein in Sedimentary Rock
Silicon Dioxide (SiO2) with host Chert or Limestone
Jasper (Green Jasper/Chert)
Silicon Dioxide (SiO2)
Sandstone
Arenite (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Quartz (specifically Clear Quartz or Rock Crystal)
Silicon Dioxide (SiO2)
Yellow Calcite
Calcium Carbonate (CaCO3)
Chalcedony (Common Opal variant)
Silicon dioxide (SiO2) with varying levels of hydration
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Basalt (Vesicular)
Vesicular Basalt
Petrified Wood
Silicified wood (Quartz, SiO2)
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Lepidolite
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2 (Lithium-bearing Phyllosilicate)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Volcanic Rock)
Sandstone
Arenite
Marble
Recrystallized Calcite (CaCO3) or Dolomite (CaMg(CO3)2)
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Limonite
Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)
Blue Sapphire
Corundum (Al2O3) with iron and titanium impurities
Almandine Garnet
Iron aluminum silicate (Fe3Al2(SiO4)3)
Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
Red Garnet (Almandine-Pyrope series)
Garnet Group, Almandine (Fe3Al2(SiO4)3) or Pyrope (Mg3Al2(SiO4)3)
Plagioclase Feldspar
Plagioclase Feldspar Series (NaAlSi3O8 - CaAl2Si2O8)