Geode (Unopened)
Crystalline Quartz Geode (SiO2)
Category
Browse mineral like biological tissue specimens identified by the Rock Identifier community.
Geode (Unopened)
Crystalline Quartz Geode (SiO2)
Diamond
Native Carbon (C)
Sandstone (specifically Banded Sandstone)
Clastic sedimentary rock (primarily SiO2)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within a metamorphic matrix
Basalt
Mafic volcanic rock, primarily composed of Plagioclase, Pyroxene, and Olivine
Bismuth Crystal
Bismuth (Bi)
Jasper
Silicon dioxide (SiO2) with impurities
Sandstone
Arenite
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurity)
Obsidian
Volcanic glass (high silica volcanic rock)
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals, Mg3Si2O5(OH)4)
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Dendritic Agate (Tree Agate)
Chalcedony (Silicon Dioxide, SiO2) with Manganese or Iron Oxide inclusions
Chalcedony (Common Opal or Agate variant)
Silicon Dioxide (SiO₂)
Petrified Wood
Silicified wood (primarily SiO2)
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Fluorite
Calcium Fluoride (CaF2)
Shale
Laminated Mudstone
Schist with Quartz/Mica
Mica Schist (primarily Muscovite and Quartz)
Celadonite in Basalt (Green Earth)
Celadonite (K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2)
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Tufa (Vesicular Limestone)
Tufa (form of Calcium Carbonate, CaCO3)
Obsidian
Volcanic Glass (70-75% SiO2)
Septarian Nodule (Dragon Stone)
Septarian Geode (CaCO3 + Mg + Fe)
Druzy Quartz Geode (Oco or Moroccan variety)
Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2 primarily)
Quartz Geode
Silicon Dioxide (SiO2)
Muscovite (White Mica)
Muscovite - Potassium aluminum silicate: KAl2(AlSi3O10)(F,OH)2
Quartz (Milky or Cloudy Quartz)
Silicon Dioxide (SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Sandstone (Picture Sandstone)
Arenite (primarily SiO2 with iron oxide impurities)
Sandstone (likely Arkosic)
Clastic Sedimentary Rock
Sandstone (likely Arkosic or Quartzose)
Sandstone (SiO2 dominated)
Limonite Concretion (Ironstone)
Limonite / Goethite (FeO(OH)·nH2O)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Ruby, Emerald, and Sapphire (Corundum and Beryl)
Corundum (Al2O3) and Beryl (Be3Al2Si6O18)
Muscovite Mica (with Quartz)
Muscovite (KAl2(AlSi3O10)(OH)2)
Red Garnet (likely Almandine or Pyrope)
Garnet group: X3Y2(SiO4)3 (e.g., Almandine: Fe3Al2Si3O12)
Biotite (Black Mica)
Biotite [K(Mg,Fe)3(AlSi3O10)(F,OH)2]
Sandstone (with banding)
Arenite (primarily SiO2)