Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Category
Mineral Description (Anthropogenic Material)
Browse mineral description (anthropogenic material) specimens identified by the Rock Identifier community.
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Petrified Wood
Silicified Wood (SiO2)
mineral
Carnelian/chalcedony rough
Microcrystalline quartz (SiO₂), iron-oxide-colored chalcedony
mineral
Sandstone
Sandstone (Quartz-rich Arenite / SiO2)
sedimentary
Black Onyx and Mother of Pearl
Cryptocrystalline Quartz (SiO2) and Nacre (Calcium Carbonate)
mineral
Laterite (Iron-rich bauxite or Gossan)
Ferricrete (Fe2O3·nH2O)
sedimentary
Quartz / Quartzite
Silicon Dioxide (SiO2)
Mineral / Metamorphic
Sandstone
Clastic Sedimentary Rock
sedimentary
Graphic Granite / Pegmatite
Graphic Granite (Alkali Feldspar and Quartz)
igneous
Sandstone
Arenite (SiO2 based with mineral cement)
sedimentary
Sandstone
SiO2 (predominantly quartz sand)
sedimentary
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of cellulose)
fossil
Sandstone with Manganese Dendrites
Arenite (mostly SiO2) with Manganese Oxide inclusions (MnO2)
sedimentary
Bicolor Quartz Tumble
Silicon Dioxide (SiO2)
mineral
Likely weathered quartz-rich stone or fossil fragment
Indeterminate; possibly quartz-bearing sandstone, iron-stained quartz, or a fragmentary fossil
mineral
Asphalt (Bituminous Rock)
Natural bitumen or Bituminous limestone/sandstone
sedimentary
Petrified Wood
Silicified wood (primarily SiO2 - Silicon Dioxide/Quartz)
metamorphic
Iron-Stained Quartz (Red Quartz)
Silicon Dioxide (SiO2) with Hematite/Limonite inclusions
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Bull Quartz (White Quartz)
Silicon Dioxide (SiO2)
mineral
Sandstone (Ferruginous)
Arenite with Iron Oxide matrix
sedimentary
Granite (Unakite / Feldspar-rich Granite)
Granite (composed of Potassium Feldspar, Quartz, and Biotite/Epidote)
igneous
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
mineral
Sandstone
Arenite (primarily SiO2)
sedimentary
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
mineral
Graphite
Graphite (Carbon, C)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Agate Nodules
Cryptocrystalline Quartz (SiO2)
mineral
Fire Opal (in Matrix)
Hydrated Silica (SiO2·nH2O)
mineral
Jasper
Silicon Dioxide (SiO2)
mineral
Jasper (likely red/brown jasper)
Microcrystalline quartz/chalcedony, SiO₂, colored mainly by iron oxides
mineral
Turquoise bead bracelet
Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O
mineral
Blue Apatite
Ca5(PO4)3(F,Cl,OH)
mineral
Sandstone
Arenite (SiO2 principal composition)
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Milky quartz pebble
Quartz (silicon dioxide, SiO₂)
mineral
Limonite (Iron Ore)
FeO(OH)·nH2O
mineral
Basaltic Tuff / Volcanic Breccia
Pyroclastic Breccia / Lithic Tuff
igneous
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Fossilized wood fragment
Petrified wood; commonly silicified fossil wood (SiO₂ replacing organic tissue)
fossil
Sandstone (likely Quartzose Sandstone pebble)
Arenite (primarily SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary