Quartzite
Quartzite (primarily SiO2)
Category
Browse organic (non geological) specimens identified by the Rock Identifier community.
Quartzite
Quartzite (primarily SiO2)
Slag Glass (Cullet)
Amorphous Silicon Dioxide (SiO2) with metal oxide colorants
Limestone with Lichen/Moss
Calcium Carbonate (CaCO3)
Quartzite
Metamorphic Quartzite
Obsidian
Amorphous volcanic glass (primarily SiO2)
Seashell (Cone Snail Shell)
Conus sp. (Calcium Carbonate, CaCO3)
Concrete rubble
Anthropogenic conglomerate
Obsidian
Obsidian (Volcanic Glass)
Obsidian
Volcanic Glass (Amorphous silicon dioxide with trace impurities)
Quartzite
Quartzite (primarily SiO2)
Slag (Industrial Glass)
Artificial Vitreous Silicate
Black Obsidian
Volcanic Glass (SiO2 + impurities)
Opalite
Man-made Opalized Glass (Synthetic Glass)
Manganese Dendrite on Siltstone
Manganese Oxide (pyrolusite or psilomelane) Dendrites
Snowflake Obsidian
Volcanic glass (SiO2) with Cristobalite (SiO2) inclusions
Glauconite (Greensand)
Glauconite (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2
Obsidian
Volcanic Glass (SiO2 dominant)
Fossiliferous Limestone / Fossil Fragment
Calcium Carbonate Matrix with Biogenic Inclusions (CaCO3)
Tufa Rock and Tumbled Gemstones
Calcareous Tufa (Calcium Carbonate, CaCO3)
Obsidian
Volcanic glass (SiO2 + impurities)
Chert (Yellow Jasper variant)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Fossiliferous Limestone
CaCO3 (principally Calcite or Aragonite)
Coral Fossil (Scleractinia)
Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)
Chert (specifically Jasper/Flint)
Microcrystalline Quartz (SiO2)
Chert (and Jasper/Chalcedony variety)
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Pink Quartzite
Quartzite (SiO2)
Snowflake Obsidian
Vitreous Volcanic Rock (Amorphous Silicate), SiO2
Obsidian
Volcanic Glass (SiO2 + impurities)
Black Obsidian
Obsidian (Amorphous Silicon Dioxide)
Granite / Feldspar gravel
Granite (felsic intrusive igneous rock)
Rose Quartz
Silicon Dioxide with traces of titanium, iron, or manganese (SiO2)
Granite
Granite (Felsic Plutonic Rock)
Green Jasper
Microcrystalline Quartz (Chalcedony), SiO2
Chert / Flint
Silicon Dioxide (SiO2)
Chert / Flint
Microcrystalline Quartz (SiO2)
Chert (Jasper)
Cryptocrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Pyrite
Iron Disulfide (FeS2)
Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Chert (Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz