Sea Glass (Uranium/Vaseline Glass variant)
Silicon Dioxide (SiO2) with trace Uranium Oxide (U3O8)
man-made silicate (anthropogenic glass)
Category
Anthropogenic (Man Made Material Processed By Nature)
Browse anthropogenic (man made material processed by nature) specimens identified by the Rock Identifier community.
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Gold-bearing Quartz
Native Gold (Au) in Quartz (SiO2) matrix
mineral
Limestone Gravel
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Red Jasper
Microcrystalline Quartz (SiO2) with iron oxide inclusions
sedimentary
Asphalt (Bituminous Concrete)
Bituminous Concrete / Pavement
man-made (synthetic rock)
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Pink Dyed Agate
Silicon Dioxide (SiO2) with synthetic pigment
mineral
Weathered iron-rich rock, possibly jasper or ironstone
Likely limonite/goethite-bearing siliceous rock; exact identification requires hardness and streak tests
mineral
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Conglomeratic gravel / polymictic breccia
Polymictic rudite, likely anthropogenic or beach/stream gravel; composition varies
sedimentary
Shale
Laminated Mudstone
sedimentary
Diamond ring
Diamond, crystalline carbon (C)
gemstone
Chert (Chert / Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Chert (specifically Jasper or Flint)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2)
sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Iron-rich breccia or weathered ironstone
Goethite–hematite-bearing ferruginous rock, possibly limonite
sedimentary
Black Tourmaline
Schorl (NaFe2+3Al6(Si6O18)(BO3)3(OH)4)
mineral
Gray Agate
Cryptocrystalline Quartz (SiO2)
mineral
Chert (Cherty Shale / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Black Tourmaline
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
mineral
Blue Topaz
Al2SiO4(F,OH)2
mineral
Diamond (or Cubic Zirconia)
Carbon (C) or Zirconium Dioxide (ZrO2)
gemstone
Chert Nodule
Microcrystalline Quartz (SiO2)
sedimentary
Chert (often called Flint in archaeological contexts)
Silicon Dioxide (SiO2)
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chert (specifically Flint)
Chert (SiO2)
sedimentary
Chert (Polished River Pebble)
Chert (SiO2)
sedimentary
Sandstone
Quartz Arenite / Sedimentary Rock
sedimentary
Red Jasper
Red Jasper (SiO2)
sedimentary
Scoria
Scoria (a vesicular basalt or andesite)
igneous
Black Tourmaline
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
mineral
Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
mineral
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Coquina (Limestone)
Bioclastic Limestone (CaCO3)
sedimentary
Tumbled serpentine
Serpentine-group minerals, chiefly antigorite, lizardite, or chrysotile; approximately Mg₃Si₂O₅(OH)₄
metamorphic
Chert
Silicon dioxide (SiO2)
Sedimentary
Engineered Quartz (Quartzite look-alike)
Silicon Dioxide (SiO2) composite
mineral-based composite