Milky Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Category
Biogenic Material
Browse biogenic material specimens identified by the Rock Identifier community.
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Quartz Vein in Sandstone
Quartz (SiO2) in Clastic Sedimentary Rock
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)
sedimentary
White quartz in dark matrix (likely quartz-bearing breccia or polished composite specimen)
Quartz, SiO₂, in an unidentified dark silicate matrix
mineral
Magnetite-rich iron ore
Magnetite (Fe₃O₄), possibly with hematite and silicate matrix
mineral
Tumbled carnelian (probable)
Cryptocrystalline silica, mainly chalcedony (SiO₂), colored orange-red by iron oxides
gemstone
Blue-beaded gemstone jewelry, likely lapis lazuli or dyed blue agate
Uncertain from the image; possible lazurite-bearing lapis lazuli (Na₃Ca(Si₃Al₃)O₁₂S) or blue chalcedony (SiO₂)
gemstone
Sapphire
Corundum (Al2O3)
gemstone
Rhodochrosite
Rhodochrosite, Manganese Carbonate (MnCO3)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Diamond
C (Carbon)
mineral
Diamond
Carbon (C)
mineral
Diamond
Carbon (C)
mineral
Travertine
Terrestrial Sedimentary Limestone (CaCO3)
sedimentary
Opalite
Man-made glass (traditionally simulated Opal)
mineral
Quartzite
Quartzite (primarily SiO2)
metamorphic
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
sedimentary
Chert (Field-collected variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Asphalt Concrete
Bituminous Concrete (Anthropic Rock)
sedimentary
Diamond
Diamond (Pure Carbon, C)
mineral
Tumbled carnelian/chalcedony
Cryptocrystalline quartz, SiO₂ (iron-bearing chalcedony)
mineral
Blue quartzite or blue aventurine glass-like aggregate
Quartzite, predominantly SiO₂ (identification uncertain from image)
metamorphic
Jasper (Banded Argillite/Chert mix)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Fossilized Bone
Permineralized Vertebrate Bone
fossil
Chert (often called Flint or Jasper)
Silicon Dioxide (SiO2)
sedimentary
Tumbled black-and-white stone, likely dendritic agate or jasper
Cryptocrystalline quartz (SiO₂), possibly chalcedony with manganese-oxide dendrites
mineral
Sandstone (Ferruginous)
Arenite (with Iron Oxides)
sedimentary
Blue Obsidian
Volcanic Glass (SiO2 with inclusions)
igneous
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
White quartz pebble
Quartz (silicon dioxide, SiO₂)
mineral
Purple fluorite (likely cubic crystal aggregate)
Fluorite, calcium fluoride (CaF₂)
mineral
Clear Quartz (Faceted) or Cubic Zirconia / Glass imitation
SiO2 (if Quartz), ZrO2 (if Cubic Zirconia)
mineral
Slate
Slate (Regional metamorphic rock composed primarily of quartz, illite, and chlorite)
metamorphic
Terrazzo (Man-made Composite)
Cementitious or Resin-bound Lithic Composite
sedimentary (artificial)
Polished green stone, likely serpentine or altered basalt
Serpentine-group minerals, chiefly Mg₃Si₂O₅(OH)₄; exact identification requires testing
metamorphic
Polished orbicular jasper (likely ocean jasper)
Jasper, microcrystalline quartz (SiO₂), colored by iron oxides and other inclusions
mineral
Tumbled pink chalcedony (likely pink agate/jasper)
Microcrystalline quartz, SiO₂, with iron-oxide coloring
mineral
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified wood / Permineralized wood (SiO2)
fossil
Mammoth or Mastodon Tooth Fossil
Mammuthus / Mammut tooth
fossil