Black Onyx
Silicon Dioxide (SiO2)
Category
Browse mineral like (natural glass) specimens identified by the Rock Identifier community.
Black Onyx
Silicon Dioxide (SiO2)
Ruby
Corundum (Al2O3 with Chromium)
Sandstone (Pebble/Conglomerate fragment)
Sandstone (clastic sedimentary rock)
Glauconitic Sandstone (Greensand)
Glauconitic Quartz Arenite (Formula: (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
Sandstone
Arenite (Sedimentary rock composed of sand-sized grains, primarily SiO2)
Snowflake Obsidian
Obsidian with Cristobalite inclusions
Peacock Ore
Bornite (Cu5FeS4)
Shale (sub-type: Carbonaceous Shale)
Lutaceous Sedimentary Rock
Dyed Agate
Agate (SiO2)
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
Shale
Fissile Mudstone
Diamond
Carbon (C), specifically in an isometric crystal system.
Chevron Amethyst
Silicon Dioxide (SiO2) with iron impurities
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
Diamond
Diamond (pure carbon, C)
Diamond (Princess Cut Faceted Gemstone)
Native Carbon (C)
Turquoise
CuAl6(PO4)4(OH)8·4H2O
Rough Diamond
Diamond (pure carbon, C)
Rough Diamond
Native Carbon (C)
Sandstone (likely Quartzose)
Arenite (primarily SiO2)
Granite
Phaneritic plutonic rock (primarily Quartz, Alkali Feldspar, and Plagioclase)
Muscovite Mica
Muscovite (Potassium Aluminum Silicate) - KAl2(AlSi3O10)(F,OH)2
Chert (specifically Blue Chert/Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Coquina (Hag Stone variant)
Biocalcarenite (Coquina)
Aventurine
Aventurine Quartz (SiO2 with inclusions)
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
Emerald
Beryl (Be₃Al₂Si₆O₁₈), specifically the green variety colored by trace amounts of chromium or vanadium.
Not a rock, mineral, or geological specimen
Sandstone
Arenite
Diamond (in jewelry setting)
Carbon (C)
Turquenite (Dyed Howlite)
Dyed Ca2B5SiO9(OH)5 (Calcium Borosilicate Hydroxide)
River Cobble (Quartzite)
Meta-orthoquartzite
Aventurine Quartz
Silicon dioxide with inclusions (KAl2(AlSi3O10)(OH,F)2)
Pink Quartz (likely dyed)
Silicon Dioxide (SiO2)
Obsidian
Volcanic glass
Fluorite Octahedron
Fluorite (Calcium Fluoride, CaF2)
Granite
Phaneritic high-silica plutonic rock (composed primarily of Quartz, Feldspar, and Mica)
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
Carnelian
Carnelian (Silicon Dioxide - SiO2 with iron oxide impurities)
Agate
Agate (Silicon Dioxide, SiO2)
Opal
Hydrated Amorphous Silica (SiO2·nH2O)