River Cobble (likely Sandstone or Siltstone type)
Sandstone or Siltstone (common rock types that form river cobbles)
Category
Browse mineral (man made glass, not natural) specimens identified by the Rock Identifier community.
River Cobble (likely Sandstone or Siltstone type)
Sandstone or Siltstone (common rock types that form river cobbles)
Black Onyx (Tumbled)
Silicon Dioxide (SiO2)
Dyed Blue Agate (Slab)
Agate (Variety of Chalcedony/Microcrystalline Quartz), SiO2
Blue Banded Agate (Dyed)
Silicon Dioxide (SiO2) - Variety of Chalcedony
Quartz
Quartz (SiO2 - Silicon Dioxide)
Shale
Fissile Mudstone (primarily composed of clay minerals and quartz grains)
Shale
Fissile mudrock (composed primarily of clay minerals and quartz)
Quartz
Quartz (SiO₂)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Slate
Foliated Metamorphic Rock (composed primarily of Quartz, Muscovite, and Illite)
Corundum
Corundum (Al2O3)
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
Sea Glass (Frosted Quartz/Glass)
Amorphous Silicon Dioxide (SiO2)
Shale
Clastic sedimentary rock (primarily clay and silt minerals)
Shale with Plant Fossils / Carbonaceous Shale
Laminated Mudrock (Siliciclastic)
Ironstone concretion / Limonitic Sandstone
Goethite/Hematite Cemented Sandstone (Hydrated Iron Oxide)
Schist (Kyanite Schist)
Kyanite-Mica Schist (primarily Al2SiO5, KAl2(AlSi3O10)(OH)2, and SiO2)
Turquoise
Hydrated copper and aluminum phosphate (CuAl6(PO4)4(OH)8·4H2O)
Black Onyx
Silicon Dioxide (SiO2) with cryptocrystalline structure
Chert (or possibly Flint)
Chert (variant: Flint)
Pearl (in a decorative hair comb setting)
Calcium carbonate (CaCO3) primarily as Aragonite, bonded with Conchiolin
Granite
Intrusive Felsic Igneous Rock
Turquoise
Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
Jadeite (Jade)
Jadeite; NaAlSi2O6
Ruby
Corundum (Aluminum Oxide with Chromium traces), Al2O3:Cr
Alexandrite
Chrysoberyl (BeAl2O4 with Chromium traces)
Gold
Native Gold (Au)
Ruby
Corundum (Al2O3 with Chromium traces)
Hematite
Iron(III) oxide (Fe2O3)
Pearl (as a Biogenic Mineral)
Calcium Carbonate (mostly Aragonite) with Conchiolin; CaCO3
Chrysocolla in Jasper (Chryso-Jasper)
Cu2-xAlx(H2-xSi2O5)(OH)4·n H2O (Chrysocolla) + SiO2 (Jasper)
Malachite
Malachite (Cu2CO3(OH)2)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
Slate
Slate (Foliated Metamorphic Rock)
Turquoise (possible Dyed Howlite or Magnesite imitation)
CuAl6(PO4)4(OH)8·4H2O (Turquoise)
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (mostly SiO2)
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)
Black Onyx
Silicon dioxide (SiO2) - Chalcedony variety
Obsidian
Volcanic Glass (SiO2 + minor impurities)
Pink Sapphire
Corundum (Al2O3) with Chromium/Iron/Titanium trace impurities
Diamond
Carbon (C), specifically a solid form of the element carbon with atoms arranged in a crystal structure called diamond cubic.