Fossilized Oyster Shell
Exogyra or Ostrea (Gryphaeidae/Ostreidae family)
fossil
Category
Mineral (Pseudomorph)
Browse mineral (pseudomorph) specimens identified by the Rock Identifier community.
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Red Sandstone
Clastic sedimentary rock (primarily SiO2 with Fe2O3)
sedimentary
Malachite
Copper carbonate hydroxide Cu2CO3(OH)2
mineral
Sandstone (Ferruginous)
Arenite (Fe-rich)
sedimentary
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 cement)
sedimentary
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
sedimentary
Sandstone with Iron Oxide Staining
Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)
sedimentary
Black Marble
Recrystallized Calcite (CaCO3)
metamorphic
Turquoise (Blue Howlite / Magnesite imitation)
CuAl6(PO4)4(OH)8·4H2O (for natural Turquoise); Ca2B5SiO9(OH)5 (for Howlite)
mineral
Red Sandstone
Arenite with iron oxide (Hematite) cement
sedimentary
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Red Sandstone
Arenite (with Iron Oxide)
sedimentary
Sandstone (Red Sandstone)
Clastic Sedimentary Rock (primarily SiO2 with Iron Oxide)
sedimentary
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 oxides)
sedimentary
Quartz crystal pendant
Quartz (silicon dioxide, SiO₂), likely rock crystal or milky quartz
mineral
Tumbled pale greenish stone, likely serpentine or altered limestone
Probable serpentine-group rock (antigorite/lizardite), possibly serpentinite; identification is visual only
metamorphic
Dark weathered igneous rock, likely basalt
Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine or iron oxides
igneous
Weathered granite or granitic gneiss
Granite; primarily quartz, feldspar, and mica (possibly metamorphosed to gneiss)
igneous
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz crystal cluster
Quartz (silicon dioxide, SiO₂)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Blue Apatite
Fluorapatite - Ca5(PO4)3F
mineral
Blue Quartz (or Blue Aventurine)
Silicon Dioxide (SiO2) with inclusions (typically Crocidolite or Dumortierite)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz (Gravel Pebble)
Silicon Dioxide (SiO2)
mineral
Quartz Veinated Sandstone or Siltstone
Silicon Dioxide (SiO2) within a clastic sedimentary matrix
sedimentary
Quartz Pebble (with Iron Staining)
Crystalline Silicon Dioxide (SiO2)
mineral
Orthoclase Feldspar
KAlSi3O8 (Potassium Aluminum Silicate)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
Mineral / Sedimentary occurrence
Quartz (Common or Milky)
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz (Microcrystalline/Macro crystalline variety)
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz (specifically Quartzite or Massive Quartz)
Silicon Dioxide (SiO2)
Mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Orthoclase Feldspar
KAlSi3O8 (Potassium aluminum silicate)
mineral