Pink Banded Agate (Dyed)
Chalcedony (cryptocrystalline silica), chemical formula SiO2
mineral
Category
Mineral Like (Natural Glass)
Browse mineral like (natural glass) specimens identified by the Rock Identifier community.
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Volcanic glass (predominantly rhyolitic SiO₂)
igneous
River Pebble (Grey Quartzite / Sandstone Gravel)
Quartz-rich Sedimentary / Metamorphic River Pebble
sedimentary
Ruby
Corundum (Al2O3)
gemstone
Tumbled orange chalcedony or jasper
Microcrystalline quartz (SiO₂), likely iron-stained chalcedony/jasper
mineral
Yellow Quartz or Citrine Geode/Cluster
Silicon Dioxide (SiO2)
mineral
Agate
Agate (Silicon Dioxide, SiO2)
mineral
Sandstone with Mineral Veining or Crust
Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)
sedimentary
Granite
Phaneritic plutonic rock (primarily Quartz, Alkali Feldspar, and Plagioclase)
igneous
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Turquoise
CuAl6(PO4)4(OH)8·4H2O
mineral
Fossilized Echinoid / Sea Urchin Internal Mold
Echinoidea internal cast (steinkern)
fossil
Clear Quartz (Faceted)
Silicon Dioxide (SiO2)
gemstone
Flint / Chert Nodule
Microcrystalline quartz (SiO2)
sedimentary
Quartzite Pebble
Quartzite
metamorphic
Howlite (Tumbled)
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
mineral
Carnelian
Carnelian (Silicon Dioxide - SiO2 with iron oxide impurities)
mineral
Banded Gneiss River Pebble
Gneiss
metamorphic
Tumbled blue-green chrysocolla (likely chrysocolla with quartz)
Chrysocolla, hydrated copper aluminum silicate; commonly intergrown with quartz, Cu₂H₂Si₂O₅(OH)₄
mineral
Green tourmaline crystal (likely elbaite)
Elbaite tourmaline, a complex borosilicate: Na(Li,Al)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄
mineral
Blue Quartz / Glass Gemstone Pendant
SiO2 (Silicon Dioxide) or Synthetic Glass
gemstone
Painted River Rock
Artificially Coated Sedimentary Rock
sedimentary
Libyan Desert Glass
Tektite (high-silica impact glass), SiO2 + tracing minerals
mineraloid / impactite
Red Granite
Phaneritic Felsic Igneous Rock
igneous
Sandstone
Arenite (Sedimentary rock composed of sand-sized grains, primarily SiO2)
sedimentary
Tumbled orange chalcedony (likely carnelian)
Microcrystalline quartz, SiO₂; iron-bearing variety commonly termed carnelian
mineral
Howlite
Howlite (Ca2B5SiO9(OH)5)
mineral
Red jasper (likely iron-rich chalcedony/jasper)
Jasper, microcrystalline quartz (SiO₂), colored mainly by hematite/goethite
mineral
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide, SiO2)
mineral
Diamond (in jewelry setting)
Carbon (C)
mineral
Strawberry Quartz (Hematoid Quartz)
Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)
mineral
Pink Granite
Granite (Phaneritic igneous rock rich in Alkali Feldspar)
igneous
Smoky Quartz with Siderite and Pyrite
Silicon Dioxide (SiO2) with Ferrous Carbonate (FeCO3) and Iron Sulfide (FeS2)
mineral
Black Tourmaline
Schorl (Na(Fe2+)_{3}Al_{6} (BO_{3})_{3} (Si_{6}O_{18})(OH)_{4})
Mineral
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Mineral (Variety of Quartz)
Diamond
Diamond (C)
gemstone
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Quartzite
Quartzite (SiO2)
metamorphic
Jasper / Flint / Chert
Microcrystalline Quartz (SiO2)
sedimentary
Yellow faceted gemstone earrings, likely citrine or yellow beryl
Citrine: quartz, SiO₂; possible yellow beryl: Be₃Al₂Si₆O₁₈
gemstone
Turquenite (Dyed Howlite)
Dyed Ca2B5SiO9(OH)5 (Calcium Borosilicate Hydroxide)
mineral
Sandstone (Pebble/Conglomerate fragment)
Sandstone (clastic sedimentary rock)
Sedimentary Rock