Silicon
Silicon (Si)
Category
Browse tektite (natural glass) specimens identified by the Rock Identifier community.
Silicon
Silicon (Si)
Smoky Quartz
Silicon Dioxide (SiO2)
Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
Chert Nodule
Microcrystalline Quartz (SiO2)
River Cobble (likely Metasedimentary)
Metasedimentary Rock / Quartz-rich Sandstone
Quartz Crystal Cluster on Matrix
Silicon Dioxide (SiO2)
Yellow Quartz Pebble
Silicon Dioxide (SiO2)
Red Coral (Precious Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
Quartz (clear quartz/crystal quartz)
Quartz, silicon dioxide (SiO₂), trigonal crystal system
Granite (Light-colored quartz/feldspar variety)
Granite (composed primarily of Quartz SiO2 and Feldspar KAlSi3O8)
Quartz (Milky or Smoky Quartz Pebble)
Silicon Dioxide (SiO2)
White quartz pebble (likely milky quartz)
Quartz, silicon dioxide (SiO₂)
Pumice
Pumice (Vesicular Rhyolite/Andesite)
Polished blue banded agate cabochon/ornamental slab
Microcrystalline quartz (chalcedony), SiO₂, with blue coloring or inclusions
Emerald (Faceted Gemstone)
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
Quartz Pebble (Hag Stone / Adder Stone)
Silicon Dioxide (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide with iron impurities (SiO2)
Amethyst and Smoky Quartz (Tumbled)
Silicon Dioxide (SiO2) with trace impurities iron (Amethyst) and aluminum/radiation (Smoky Quartz)
Quartz (Smoky/Druzy variety)
Silicon Dioxide (SiO2)
Blue Topaz
Topaz [Al2SiO4(F,OH)2]
Weathered sandstone or iron-stained sedimentary rock
Likely quartz-rich sandstone; exact identification is uncertain from the photograph
White seed-bead gemstone strand, likely freshwater pearl or shell pearl
Pearl: nacreous calcium carbonate, chiefly aragonite (CaCO₃) in conchiolin; identification uncertain from image
Jasper
Silicon Dioxide (SiO2) with impurities
Pink Granite (Water-worn Cobble)
Phaneritic Felsic Intrusive Igneous Rock
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2AlSi3O10(OH)2)
Green Aventurine
Quartz (SiO2) with Fuchsite inclusions
Aventurine
Quartz containing inclusions of Fuchsite (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
Emerald in Host Rock
Beryl (Be3Al2Si6O18) containing Chromium and/or Vanadium
Smoky Quartz
Silicon Dioxide (SiO2)
Sandstone
Arenite (Siliclastic sedimentary rock)
Polished white agate or chalcedony bead
Microcrystalline quartz (SiO₂), likely chalcedony/agate with iron-oxide staining or a brown mineral inclusion
Quartzite
Quartzite (composed primarily of silica, SiO2)
Opalite
Synthetic Glass (Hydrated Crystalline Silicon Dioxide simulation)
Citrine Quartz
Silicon Dioxide (SiO2)
Amethyst Quartz
Silicon Dioxide (SiO2) with iron impurities
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Tumbled quartz pebble
Quartz (SiO₂), likely milky or iron-stained quartz
Sandstone (Quartzose)
Arenite (SiO2 principal composition)
Artificial Rock Face (Faux Rock)
Glass Fiber Reinforced Concrete (GFRC)
Flint / Chert
Microcrystalline Quartz (SiO2)
Strawberry Quartz (Hematoid Quartz)
Silicon Dioxide with Hematite/Goethite inclusions (SiO2 + Fe2O3)