Chert (specifically varieties like Chalcedony or Flint)
Silicon Dioxide (SiO2)
sedimentary
Category
Manufactured Stone
Browse manufactured stone specimens identified by the Rock Identifier community.
Tumbled pale quartz/chalcedony fragment
Quartz (SiO₂), possibly microcrystalline chalcedony
mineral
Fossil fish slab
Fossilized fish remains, likely a laminated shale-hosted vertebrate fossil; exact taxon is indeterminate from the image
fossil
Black tourmaline (schorl) crystal fragments
Schorl, NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄
mineral
Sandstone (likely Fossilized Wood or Concrete Simulacrum)
Arenite / Silicified Wood / Anthropogenic Concrete
sedimentary
Green Sea Glass
Man-made vitreous material (silica glass)
gemstone
Colorless faceted quartz-like gemstone
Likely quartz (SiO₂), though the appearance may also indicate man-made glass or cubic zirconia
gemstone
Blue-and-white opalite sphere
Opalite (commercial synthetic or glass-based imitation; not true opal), typically silica glass or synthetic opalescent material
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Milky Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Opalite
Synthetic Glass (Simulated Opal)
gemstone
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Sandstone or Weathered Conglomerate
Sedimentary Rock (Quartzose Sandstone / Lithic Arenite)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
White Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Fossilized coral or silicified organic limestone
Likely fossil coral (Scleractinia/Tabulata) replaced or cemented by calcite and silica; exact identification requires close examination
fossil
Iridescent polished gemstone, likely opal
Common or precious opal (hydrated amorphous silica, SiO₂·nH₂O), possibly synthetic or glass imitation
gemstone
Silver (Sterling Silver)
Argentum (Ag) mixed with Copper (Cu); Formula: Ag+Cu
mineral
Fossilized bivalve or brachiopod shell
Mineralized carbonate shell, commonly calcite (CaCO₃); exact taxon indeterminate from image
fossil
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Native silver fragment (probable)
Silver, Ag; possibly silver-bearing sulfide or plated metal
mineral
Sea Glass (Uranium/Vaseline Glass variant)
Silicon Dioxide (SiO2) with trace Uranium Oxide (U3O8)
man-made silicate (anthropogenic glass)
Beads (likely glass or man-made material)
N/A (artificial material)
Man-made material, not a natural rock or mineral specimen
Chert
Silicon Dioxide (SiO2)
sedimentary
Chert
Silicon Dioxide (Microcrystalline Quartz)
sedimentary
Tumbled goldstone-like quartz pebble
Likely iron-stained quartz or jasper; exact identification requires testing
mineral
Opalite (likely man-made opalescent glass)
Opalite; not a true mineral, typically synthetic opalescent glass (silica-based)
mineral
Opalite
Synthetic Glass (Simulated Moonstone/Opal)
gemstone
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Quartz Pebble
Quartz (SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Sandstone (likely with Quartz Veining)
Arenite (primarily SiO2)
sedimentary
Sandstone
Clastic Sedimentary Rock
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Sandstone
Sedimentary Clastic Rock (Quartz-rich)
sedimentary
Quartz (Tumbled)
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Sandstone
Sedimentary Rock (Quartzose Sandstone)
sedimentary
Sandstone
Arenite
sedimentary
Sandstone Cobble
Arenite (primarily SiO2)
sedimentary