Shale
Shale (clastic sedimentary rock)
Category
Browse mineral like (natural glass) specimens identified by the Rock Identifier community.
Shale
Shale (clastic sedimentary rock)
Weathered Sandstone
Quartz Arenite / Clastic Sedimentary Rock
Amethyst (Resin Carving/Orgonite)
Silicon Dioxide (SiO2) with iron impurities
Granite
Intrusive Felsic Igneous Rock
Turquoise
CuAl6(PO4)4(OH)8·4H2O
Orange Quartz (Citrine Quartz)
Silicon Dioxide (SiO2)
Amethyst cluster
Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation
Blue Lace Agate (often dyed)
Silicon dioxide (SiO2) - variety of chalcedony
Sandstone
Arenite (predominantly Quartz Sandstone)
Blue Sapphire Crystal (Rough)
Corundum (Aluminum Oxide, Al2O3)
Citrine Quartz
Citrine (Silicon Dioxide, SiO2)
Tumbled Mixed Gemstones (Quartz and Rutile)
Silicon Dioxide (SiO2) with various inclusions
Shale with Iron Oxide Staining
Fissile Mudstone (primarily clay minerals and quartz)
Black Onyx
Black Chalcedony (SiO2)
Dragon's Breath (Mexican Opal Glass)
Artisan Foil Glass (SiO2 based)
Generic Rock / Pebble
Undetermined rock specimen
Peacock Ore
Bornite (Cu5FeS4)
Amethyst Cluster
Silicon Dioxide (SiO2 with iron impurities)
Smoky Quartz
Silicon Dioxide (SiO2)
Smoky Quartz
Smoky Quartz (Silicon Dioxide, SiO2)
Yellow Quartz (Citrine Quartz variety / Ferruginous Quartz)
Silicon Dioxide (SiO2) with iron inclusions
Ocean Jasper Mushroom
Orbicular Jasper (Silicon Dioxide, SiO2 mixed with various impurities)
Smoky Quartz
Silicon dioxide (SiO2)
Smoky Quartz in Matrix
Silicon dioxide (SiO2) within Pegmatite/Gneiss
Amethyst (Purple Quartz)
Silicon Dioxide (SiO2) with iron impurities
Black Onyx
Silicon Dioxide (SiO2)
Diamond
Diamond (pure native carbon, C)
Red Sandstone
Quartzose Sandstone (SiO2)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
Blue Sapphire
Corundum (Al2O3)
Green Aventurine
Quartz with Fuchsite inclusions (SiO2)
Slag (Industrial Byproduct)
Anthropogenic Vitreous Silicate material
Agate (specifically, multi-colored or pastel-dyed agate)
Silicon dioxide (SiO2) - specifically, a cryptocrystalline variety of quartz known as Chalcedony, with banding classified as Agate. (If it were Fluorite, the chemical formula would be Calcium Fluoride - CaF2).
Granite
Granite
Snowflake Obsidian
Volcanic Glass with Spherulite inclusions (mainly Cristobalite)
Hag Stone
Perforated Sedimentary Rock (typically Limestone or Sandstone)
Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
Tumbled or rough turquoise-like specimen
Turquoise, hydrated copper aluminum phosphate — CuAl₆(PO₄)₄(OH)₈·4H₂O; identification is uncertain from the image
River Cobble (Quartzite or Sandstone)
Clastic sedimentary rock (primarily SiO2)
Smoky Quartz (Tumbled/Water-worn Quartz)
Silicon Dioxide (SiO2)
Chert Nodule
Microcrystalline Quartz (SiO2)
Iron-Stained Quartz
Silicon Dioxide with Iron Oxide (SiO2 with Fe2O3)