Opalite
Synthetic Glass (Simulated Moonstone/Opal)
Category
Browse anthropogenic (man made material processed by nature) specimens identified by the Rock Identifier community.
Opalite
Synthetic Glass (Simulated Moonstone/Opal)
Quartz (likely milky quartz or quartz glass-like fragment)
Quartz, silicon dioxide (SiO₂)
Strawberry Quartz
Silicon Dioxide (SiO2) with Hematite/Goethite inclusions
Milky quartz (rough quartz fragment)
Quartz, silicon dioxide (SiO₂)
Chert Concretion
Chert (Microcrystalline Quartz, SiO2)
Boxwork or Septarian Concretion
Septarian nodule / Boxwork weathering
Opalite
Synthetic Opalized Glass
Cobalt Glass Slug (Cullet)
Man-made Silicate Glass with Cobalt Oxide (CoO)
Opalite
Man-made opalescent glass (SiO2 + metal oxides)
Crushed Stone Ballast
Crushed Limestone or Granite Aggregate
Sea Glass
Man-made silicate glass (Amorphous silicon dioxide)
Possible obsidian or slag glass
Volcanic glass, primarily SiO₂; alternatively industrial iron-rich glassy slag
Granite
Granite (Felsic Plutonic Rock)
Polished blue calcite sphere (tentative identification)
Calcite, CaCO₃; blue color generally results from trace impurities or inclusions
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Clear quartz sphere
Quartz (silicon dioxide, SiO₂)
Diamond (in a gold ring)
Diamond (pure carbon, C)
Pink Quartz / Sea Glass
Silicon Dioxide (SiO2)
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
Coquina
Coquina (Bioclastic Limestone)
Chert Arrowhead (Projectile Point)
Microcrystalline Quartz (SiO2)
Slag (Industrial Glassy Byproduct)
Anthropogenic silicate byproduct (Slag)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz pebble in concrete
Quartz (SiO₂), embedded in Portland-cement concrete
Diamond
Carbon (C)
Nutting Stone / Cupstone (Sandstone or Quartzite)
Sedimentary rock with anthropogenic modification (cupule)
Clear quartz crystal (likely)
Quartz, silicon dioxide (SiO₂)
Crushed Limestone
Calcium Carbonate (CaCO3)
Iron Slag
Anthropogenic Vitreous Ferrous Silicate
Opalite (a synthetic glass, often confused with Opal)
Silicon dioxide glass (SiO2nH2O, for natural opal)
Rock crystal quartz fragments
Quartz (silicon dioxide, SiO₂)
Dyed Howlite (simulating Lavender/Purple Jade or Charoite)
Howlite: Ca2B5SiO9(OH)5 (when natural)
Crushed Granite and Quartz Gravel
Composite Igneous and Silicate Rock Aggregate
Tumbled opalite (likely synthetic glass)
Opalite; typically man-made opalescent soda-lime glass, not a recognized mineral species
Tumbled lavender quartz (likely lepidolite-bearing quartz or dyed quartz)
Quartz, SiO₂; possible lepidolite mica inclusions
Dyed, polished stone beads (likely assorted agate or jasper)
Microcrystalline quartz, SiO₂ (chalcedony; exact stones cannot be determined from the image)
Polished gemstone tower assortment
Primarily quartz varieties and simulants; apparent amethyst (SiO₂), rose quartz (SiO₂), clear quartz (SiO₂), fluorite (CaF₂), sodalite, malachite, and possibly dyed or composite stones
Citrine Quartz / Yellow Quartz Pebbles
Silicon Dioxide (SiO2)
Green Slag Glass
Amorphous Silica Glass (Anthropogenic)
Slag (Industrial Glass)
Anthropogenic Amorphous Vitreous Silicate
Clear quartz crystal (likely)
Quartz, silicon dioxide (SiO₂)
Polished dendritic agate or jasper
Microcrystalline quartz (SiO₂), likely chalcedony with iron/manganese dendrites