Pumice
Pumice (Vesicular volcanic glass)
Category
Browse man made silicate (anthropogenic glass) specimens identified by the Rock Identifier community.
Pumice
Pumice (Vesicular volcanic glass)
Basalt with Iron Oxidation
Amygdaloidal Basalt (silicate rock primarily plagioclase, pyroxene, and olivine)
Chert (Gravel)
Chert (Cryptocrystalline silicon dioxide, SiO2)
Apache Tears (Obsidian)
Hydrated Volcanic Glass (Amorphous SiO2 + H2O)
Quartz Geode (Water-worn)
Silicon Dioxide (SiO2)
Agate
Banded Chalcedony (SiO2)
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Oolitic Chert
Silicon Dioxide (SiO2) with oolitic texture
Beryl (likely Aquamarine) in matrix
Be3Al2(SiO3)6 (Beryllium Aluminum Silicate)
Dyed Quartz (often sold as 'Blue Quartz' or 'Blue Agate')
Silicon Dioxide (SiO2) with artificial pigment
Yellow Jade (often Serpentine or Dolomite)
Primarily Serpentine (Mg3Si2O5(OH)4) or Dolomite (CaMg(CO3)2), though the term 'yellow jade' is also sometimes applied to varieties of true nephrite or jadeite.
Sandstone (Ferruginous)
Arenite (with iron oxide cement)
Aquamarine
Beryllium Aluminum Silicate (Be3Al2Si6O18)
Obsidian
Volcanic Glass (70-75% SiO2)
Tektite (Indochinite)
Tektite (High-silica natural glass, primarily SiO2 with Al2O3)
Obsidian
Volcanic glass (high silica content, usually >70% SiO2)
Moldavite
Silica glass with small amounts of aluminum, iron, and other elements
Sandstone
Sandstone (Clastic Sedimentary Rock)
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite inclusions (SiO2)
Snowflake Obsidian
Volcanic glass containing Spherulitic Cristobalite (SiO2)
Snowflake Obsidian
Vitreous Volcanic Glass (Siliceous Obsidian with Cristobalite inclusions)
Chert (Arrowhead/Tool Grade)
Microcrystalline Quartz (SiO2)
Sandstone or Quartzite
Arenite (if sedimentary) / Quartzite (if metamorphic)
Chert (Gravel Bit)
Microcrystalline silica (SiO2)
Snowflake Obsidian
Spherulitic Volcanic Glass (SiO2 + impurities)
Snowflake Obsidian
Volcanic Glass (SiO2 + impurities)
Snowflake Obsidian
Volcanic glass containing Spherulite inclusions (primarily Cristobalite, SiO2)
Obsidian
Volcanic Glass (comprised primarily of SiO2)
Jasper (Iron-stained Chert)
Silicon Dioxide (SiO2)
Quartz Druzy on Agate (River Cobble)
Silicon Dioxide (SiO2)
Quartz with Iron Staining
Silicon Dioxide (SiO2) with FeOx inclusions
Chert (specifically Red Chert or Jasper)
Microcrystalline Quartz (SiO2)
African Turquoise (Jasper)
Polychrome African Jasper (often marketed as 'African Turquoise' due to its color, but it is not true turquoise)
Herkimer Diamond
Quartz (Silicon Dioxide, SiO2)
Jasper (likely a variety of Brecciated Jasper or a patterned variety)
Silicon dioxide (SiO2)
Shiva Lingam
Cryptocrystalline Quartz (Jasperiod Silicate with Iron Oxide inclusions)
Beryl (Variety: Aquamarine/Green Beryl)
Beryllium Aluminum Silicate (Be3Al2Si6O18)
White Topaz
Topaz [Al2SiO4(F,OH)2]
Marble
Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.
Grey Granite
Phaneritic Felsic Intrusive Igneous Rock
Coral Fossil (Petrified Coral)
Scleractinia (Order) - Calcified Fossil Skeleton (CaCO3)