Snowflake Obsidian (Flower Jasper variant)
Vitreous volcanic silicate with cristobalite inclusions
igneous
Category
Man Made Byproduct (Often Mistaken For Obsidian Or Emerald)
Browse man made byproduct (often mistaken for obsidian or emerald) specimens identified by the Rock Identifier community.
Man-made Jewelry Charm (Enameled Metal)
Not a natural mineral; composed of base metal alloy (likely zinc or brass) and epoxy resin/enamel.
Synthetic / Manufactured Artifact
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
mineral
Green Aventurine (Quartz)
Silicon Dioxide (SiO2) with inclusions of Fuchsite
metamorphic
Chert (Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Sodalite
Sodalite, Na8(Al6Si6O24)Cl2
mineral
Chert (specifically Jasper or Flint variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Quartzite (Iron-stained)
Quartzite (mostly SiO2 with Fe2O3 impurities)
metamorphic
Ferruginous Quartz
Silicon Dioxide (SiO2) with iron oxide inclusions
mineral
Ironstone Concretion (Limonite/Goethite)
Ferruginous Sandstone / Ironstone (FeO(OH)·nH2O)
sedimentary
Specular Hematite (Specularite)
Iron Oxide (Fe2O3)
mineral
Terrazzo (with Marble and Granite fragments)
Cementitious or resinous composite containing Calcium Carbonate (CaCO3) and Silicates
sedimentary (man-made composite)
Pyrite
Iron Sulfide (FeS2)
mineral
Sandstone with Ironstone Concretion
Arenite with Hematite/Goethite nodules (Fe2O3 / FeO(OH))
sedimentary
Chert (and/or Flint)
Chert (Cryptocrystalline variety of Quartz, SiO2)
sedimentary
Granite
Granite (a phaneritic intrusive igneous rock)
igneous
Citrine (Yellow Quartz)
Silicon Dioxide (SiO2)
Mineral
Smoky Quartz
Smoky Quartz (Silicon Dioxide, SiO2)
mineral
Fired Clay Brick (Anthropic Rock substitute)
Anthropogenic polycrystalline ceramic (predominantly Mullite and Quartz: Al6Si2O13 + SiO2)
metamorphic (man-made / anthropic)
Chert (Nodular or Massive Variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Obsidian (Apache Tear)
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
igneous
Chert (Iron-Stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Chert (varietal Chalcedony or Flint)
Silicon dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Quartz (possibly milky quartz)
Quartz (Silica; SiO₂)
Mineral
Chert (variations include Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Sapphire (likely blue synthetic sapphire or blue glass in a ring)
Corundum (Al₂O₃), specifically the blue variety due to trace amounts of iron and titanium impurities. If synthetic, it would still be Al₂O₃.
Mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Petrified Wood (Silicified Wood)
Silicified Paleoflora (mainly Quartz, SiO2)
metamorphic
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
sedimentary
Ferruginous Quartzite (Red Chert/Jasper-like)
Metamorphosed Quartzite with Hematite inclusions (SiO2 + Fe2O3)
metamorphic
Diorite
Diorite
igneous
Green Aventurine
Quartz (SiO2) containing Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
metamorphic
Blue Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
mineral
Siltstone
Siltstone (composed of clastic quartz and feldspar)
sedimentary
Granodiorite
Granodiorite
igneous
Tektite (Indochinite)
Tektite (Silica-rich natural glass)
mineral
Obsidian (Apache Tear)
Obsidian (Amorphous Volcanic Glass / SiO2 with impurities)
igneous
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
mineral
Quartz with Iron Staining
Silicon Dioxide (SiO2) with Limonite/Hematite inclusions
mineral
Porcelain (Stoneware Ceramic)
Mullite / Silica-glass composite (Al6Si2O13)
metamorphic (man-made)
Sunstone
Aventurine Feldspar (Plagioclase Feldspar with inclusions)
mineral
Osumilite in Granite Matrix
(K,Na)(Fe,Mg)2(Al,Fe)3(Si,Al)12O30
mineral