Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
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.
Serpentine
Serpentinite (rock), Serpentine group minerals (e.g., Antigorite, Lizardite, Chrysotile)
Metamorphic rock
Limonite Concretion (Ironstone)
Limonite (FeO(OH)·nH2O) / Goethite
sedimentary
Jadeite Jade
NaAlSi2O6 (Sodium Aluminum Silicate)
metamorphic
Chert (Tan/Brown variety)
Chert (Silicon Dioxide, SiO2)
sedimentary
Dumortierite Quartz
Al7BO3(SiO4)3O3 (Borosilicate mineral/Quartz inclusion)
mineral
Snowflake Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)
igneous
Concretion with Quartz Veining
Septarian Concretion (CaCO3 / SiO2)
sedimentary
Chert (often called Flint in archaeological contexts)
Silicon Dioxide (SiO2)
sedimentary
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
mineral
Sandstone
Clastic sedimentary rock (Quartz arenite/Arkose)
sedimentary
Chert (Common Opal/Jasper variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2)
sedimentary
Chinese Writing Stone
Porphyritic Basalt (or Andesite) with Feldspar inclusions
igneous
Granodiorite
Granodiorite (phaneritic intrusive igneous rock)
igneous
Sodalite
Sodalite, Na8(Al6Si6O24)Cl2
mineral
Orange Quartz
Crystalline Silicon Dioxide (SiO2) with iron oxide inclusions
mineral
Man-made Synthetic Material (Not a rock or mineral)
Polyester (Polyethylene terephthalate) / Faux Fur
Synthetic / Textile
Snowflake Obsidian
Volcanic glass containing Spherulites (SiO2)
igneous
Fossiliferous Limestone
Limestone (composed primarily of calcite with included fossils CaCO3)
Sedimentary
Belemnoit (Fossil)
Belemnoidea (Order), Rostrum / Guard
sedimentary
Dumortierite Quartz
Dumortierite-bearing Quartz (Al7BO3(SiO4)3O3)
metamorphic
Ironstone Concretion (Siderite Nodules)
Siderite (FeCO3) in Mudstone or Sandstone matrix
sedimentary
Chert / Flint
Chert (varieties include Flint)
Sedimentary
Chert (and/or Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Obsidian Arrowhead
Volcanic Glass (70% or more SiO2)
Igneous
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Blue Quartz (specifically Dumortierite Quartz)
Silicon Dioxide (SiO2) with inclusions of Dumortierite (Al7BO3(SiO4)3O3)
metamorphic
Ironstone Concretion / Limonite
Goethite and Limonite (FeO(OH)·nH2O)
sedimentary
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (mostly SiO2)
igneous
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
mineral
Sandstone Chert Concretion
Silica-cemented Concretion (primarily SiO2)
sedimentary
Snowflake Obsidian
Spherulitic Volcanic Glass (SiO2 + impurities)
igneous
Dalmatian Stone
Dalmatian Jasper (actually a Peralkaline Igneous Rock)
igneous
Sandstone Cobble with Liesegang Rings
Arenite with iron oxide precipitation (SiO2 matrix with Fe2O3 banding)
sedimentary
Blue Apatite
Apatite group (Ca5(PO4)3(F,Cl,OH))
mineral
Sandstone with Concretions / Liesegang Rings
Arenite with iron oxide banding
sedimentary
Quartz (Iron-Stained)
Silicon Dioxide (SiO2)
mineral
Quartz with Mica inclusions (Gold-colored Mica)
Silicon Dioxide (SiO2) with Potassium Aluminum Silicate (Phlogopite/Muscovite) inclusions
Mineral
Concretion
Septarian concretion (likely containing Calcite or Siderite)
sedimentary
Tektite (Indochinite)
Tektite (High-silica natural glass)
igneous