Obsidian (specifically Rainbow or Silver Sheen Obsidian)
Volcanic Glass (predominantly SiO2)
Igneous
Category
Mineral, Specifically A Rock Fragment
Browse mineral, specifically a rock fragment specimens identified by the Rock Identifier community.
Orbicular Granite (specifically Mustard or Yellow Tonalite/Granodiorite)
Orbicular Quartz Diorite / Tonalite
igneous
Coquina
Bioclastic Limestone
sedimentary
Emerald
Beryl (Be3Al2Si6O18), specifically the green variety colored by chromium or vanadium
Mineral (Gemstone variety of Beryl)
Slag Glass
Glassy Silicate Residue
industrial byproduct
Serpentinite (often called Jade or Nephrite substitute)
Serpentinite (composed primarily of Antigorite, Lizardite, or Chrysotile)
metamorphic
Brecciated Jasper
Silicon Dioxide (SiO2) with Hematite and Quartz inclusions
sedimentary
Quartz on Matrix
Silicon Dioxide (SiO2)
mineral
Fossiliferous Limestone
Limestone (composed primarily of calcite with included fossils CaCO3)
Sedimentary
Chert (specifically Flint)
Silicon dioxide (SiO2)
sedimentary
Chert (specifically Flint)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Blue Goldstone
Aventurine Glass (Silicon Dioxide infused with Cobalt/Copper)
Synthetic (Man-made Glass)
Black Jasper
Silicon Dioxide (SiO2) with Carbonaceous inclusions
sedimentary
Mahogany Obsidian
Volcanic glass (SiO2 with Hematite or Magnetite inclusions)
igneous
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Not a rock
Not a rock
Not a rock
Fossiliferous Limestone (Coquina / Shell Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Coquina
Bioclastic Limestone (composed of CaCO3)
sedimentary
Orthoclase Feldspar
Potassium Aluminum Silicate (KAlSi3O8)
mineral
Emerald
Beryl (Be3Al2(SiO3)6) with trace Chromium/Vanadium
mineral
Orange Calcite
Calcite (CaCO3)
Mineral
Amber (Black)
Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)
Mineraloid
Amber
Succinite (Organic Mineraloid) - C10H16O
mineral
Coquina (Limestone)
Bioclastic Limestone (CaCO3)
sedimentary
Manganese Oxide Crust on Limestone
Manganese Oxides (e.g., Pyrolusite MnO2 or Romanechite) on CaCO3
sedimentary
Agate
Silicon Dioxide (SiO2) - variety Chalcedony
mineral
Fossiliferous Limestone
Biogenic Calcium Carbonate (CaCO3)
sedimentary
Quartz (Druzy) in host rock
SiO₂ (Silicon Dioxide) as Quartz, with unspecified host rock components (likely silicates and iron oxides)
Mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Dalmatian Jasper / Dalmatian Stone
Peralkaline Rock (Silicon Dioxide with Amphibole inclusions)
igneous
Serpentine
Antigorite, Lizardite, or Chrysotile (Mg, Fe)3Si2O5(OH)4
metamorphic
Quartz Vein in Sedimentary Rock
Silicon Dioxide (SiO2) with host Chert or Limestone
mineral
Note: Item is not a geological specimen
Homo sapiens (Dermal Appendage: Pilus)
Organic / Biological
Basalt with Quartz/Calcite Veins
Amygdaloidal Basalt (SiO2 or CaCO3 inclusions)
igneous
Granitic Gneiss
Gneiss (Metamorphic Rock)
metamorphic
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Coquina / Fossiliferous Limestone
Fossiliferous Calcarenite (Calcium carbonate, CaCO3)
sedimentary
Quartz (Druzy)
Silicon Dioxide (SiO2)
mineral
Slickenside
Tectonic Fault Scarp Surface
metamorphic
Iron Meteorite
Iron-Nickel Meteorite (primarily composed of kamacite and taenite alloys)
Mineral
Lapis Lazuli (Low Grade)
Lazurite-rich metamorphic rock ((Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2)
metamorphic