Tumbled purple chalcedony or low-grade amethyst bead bracelet
Chalcedony (microcrystalline SiO₂), possibly quartz/amethyst; composition is SiO₂
mineral
Category
Man Made Material (Simulated Mineral)
Browse man made material (simulated mineral) specimens identified by the Rock Identifier community.
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Coquina
Biogenic Limestone (Calcite/Aragonite base, CaCO3)
sedimentary
Engineered Quartz Stone
Agglomerated Quartz (SiO2 + Polymer Resin)
mineral-based composite
Aura Quartz / Rainbow Aura Quartz
Silicon Dioxide (SiO2) with metallic vapor coating
mineral
Sandstone
Arenite
sedimentary
Fossil coral in limestone
Fossilized colonial coral, likely tabulate or favositid coral (CaCO₃), preserved in calcitic limestone
fossil
Diamond (in jewelry setting)
Diamond (C - Carbon)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Sandstone
Clastic sedimentary rock (Quartz arenite/Arkose)
sedimentary
Turquoise (beads)
Turquoise; CuAl6(PO4)4(OH)8·4H2O
Mineral
Dark gneiss or migmatitic amphibolite
Band ed gneiss; composition likely quartz–feldspar–biotite/amphibole, possibly migmatite
metamorphic
Megalodon Shark Tooth
Otodus megalodon
fossil
Polished black stone sphere, likely obsidian
Obsidian — naturally occurring volcanic glass, chiefly silica-rich rhyolitic glass
igneous
Sandstone
Arenite
sedimentary
Corundum (Pink Sapphire / Ruby)
Al2O3 (Aluminum Oxide)
mineral
Sandstone (with iron staining)
Quartz Arenite / Ferruginous Sandstone
sedimentary
Goldstone
N/A (Synthetic Glass with Copper Inclusions)
Manufactured Glass
Chert (Cherty Shale / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
White quartz bead bracelet (likely milky quartz)
Quartz, silicon dioxide (SiO₂), usually microcrystalline or cloudy crystalline quartz
mineral
Diamond (as set in a metal alloy ring)
Diamond (Pure Carbon, C)
mineral
Chert (flint)
Microcrystalline quartz, SiO₂ (chalcedony/quartz)
sedimentary
Tumbled greenstone, likely nephrite jade
Nephrite jade (interlocking tremolite–actinolite amphibole; Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂)
metamorphic
Bituminous Coal (with Anthracite or Vitrinite inclusion)
Organic-rich Sedimentary Rock (Carboniferous classification)
sedimentary
Chert (Siltstone / Flint)
SiO2 (Cryptocrystalline Quartz)
sedimentary
Blue Goldstone
Aventurine glass (Synthetic borosilicate glass with cobalt and metallic inclusions)
man-made glass
Coquina
Bioclastic Limestone
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Sandstone
Arenite
sedimentary
Likely flint pebble (possibly a worked flint fragment)
Microcrystalline quartz (chalcedony), SiO₂; commonly called flint
sedimentary
Coquina (Fossiliferous Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Diorite (Gneissic)
Diorite
igneous
Stone bead bracelet
Unidentified polished natural-stone beads; possibly wood-grain jasper, agate, or serpentine
mineral
Blue-stone and diamond ring
Blue stone is possibly blue sapphire (corundum, Al₂O₃); surrounding stones appear to be diamonds (carbon, C).
gemstone
Colorless faceted gemstone, likely quartz
Quartz (SiO₂), tentative identification; the photo is insufficient to confirm the material
gemstone
Flint (chert) nodule
Microcrystalline quartz (SiO₂), a variety of chert
sedimentary
Chert (varieties: Flint or Jasper)
Silicon dioxide (SiO2) / Microcrystalline Quartz
sedimentary
Banded Chert (River Stone)
Silicon Dioxide (SiO2)
sedimentary
Chert / Flint
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Chert (Commonly known as Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper/Common Chert Pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Bauxite
Bauxite (Al(OH)3, AlO(OH))
sedimentary