Diamond
Natural Diamond (Carbon, C)
mineral
Category
Mineral Description (Anthropogenic Material)
Browse mineral description (anthropogenic material) specimens identified by the Rock Identifier community.
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Granite
Intrusive igneous rock composed mainly of quartz, alkali feldspar, and plagioclase
igneous
Tumbled jasper (likely brecciated or orbicular jasper)
Microcrystalline quartz (SiO₂), with iron-oxide inclusions
mineral
Milky Quartz (among River Rock)
Quartz (Silicon Dioxide, SiO2)
Mineral
Red Sandstone (Iron-rich)
Ferruginous Sandstone (SiO2 with Iron Oxides)
sedimentary
Tumbled green aventurine (likely)
Quartz, SiO₂, containing green fuchsite mica or other inclusions
mineral
Quartz crystal pendant
Quartz (silicon dioxide, SiO₂), likely rock crystal or milky quartz
mineral
Quartz with inclusions
Silicon Dioxide (SiO2)
mineral
Red Sandstone
Arenite (Iron-rich)
sedimentary
Quartzite with inclusions
Quartzite
metamorphic
Green cabochon gemstone pendant, likely turquoise or dyed green turquoise
Probably turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O; exact identification requires testing
gemstone
Sandstone (likely Arkose or Quartz Sandstone)
Arenite (SiO2 principal component)
sedimentary
Red Sandstone
Ferruginous Sandstone (SiO2 with Fe2O3)
sedimentary
Ironstone Concretion (Limonite/Hematite Nodules)
Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)
sedimentary
Red Tuff / Sandstone
Rhyolitic Tuff / Pyroclastic Volcanic Rock
igneous
Turquoise
CuAl6(PO4)4(OH)8·4H2O
mineral
Blue magnesite beads
Magnesite (MgCO₃), likely stabilized or dyed; brown veining may reflect matrix or iron oxides
mineral
Cream River Jasper
Silicified microcrystalline quartz (SiO2)
sedimentary
Sandstone with Iron Staining
Arenite (SiO2 with Fe2O3)
sedimentary
Polished brecciated jasper
Jasper, opaque microcrystalline quartz (SiO₂), likely brecciated jasper with iron-oxide and dark silicate inclusions
mineral
Polished agate slice
Agate, a banded variety of chalcedony (microcrystalline SiO₂)
mineral
Travertine (Calcareous Tufa)
Calcium Carbonate (CaCO3)
sedimentary
Blue-green copper mineral specimen, likely chrysocolla-bearing rock
Chrysocolla, hydrated copper phyllosilicate: approximately (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O; possibly mixed with malachite or chrysocolla matrix
mineral
Schist (with Iron Oxide)
Mica Schist
metamorphic
Fossilized Bivalve Shell
Class Bivalvia (fossilized)
fossil
Seashell Fossil
Gastropoda fossil
fossil
Fossilized Coral
Cnidaria (Hexacorallia)
fossil
Fossil Snail
Gastropoda fossil
fossil
Opalite
Synthetic Opalized Glass
gemstone
Sandstone
Arenite (SiO2 predominantly)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
fossil
Shark Tooth Fossil
Carcharodonta (order Lamniformes), likely Carcharias spp.
fossil
Petrified Wood
Silicified Wood (SiO2)
mineral
Pearl and Garnet Glass
Calcium Carbonate (CaCO3) for pearl; Silicon Dioxide (SiO2) for glass
mineral and glass
Megalodon Shark Tooth Fossil
Otodus megalodon (fossilized in sedimentary matrix)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Jasper
Silicon dioxide (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Garnetiferous Pegmatite
Pegmatite with Almandine Garnet and Muscovite
igneous
Red jasper (likely hematite-rich jasper)
Microcrystalline quartz (SiO₂) with iron oxides, chiefly hematite (Fe₂O₃)
mineral
Coquina
Coquina (Bioclastic Limestone)
sedimentary