Sandstone
Arenite (SiO2 based)
sedimentary
Category
Sedimentary (Secondary Mineral Formation)
Browse sedimentary (secondary mineral formation) specimens identified by the Rock Identifier community.
Learn about Sedimentary (Secondary Mineral Formation) in the encyclopedia
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Quartzite Pebble
Metamorphic Quartz-rich Rock (SiO2)
metamorphic
Shale with Quartz Veins
Fissile Sedimentary Rock (SiO2)
sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Turquoise
Hydrated phosphate of copper and aluminium - CuAl6(PO4)4(OH)8·4H2O
mineral
Limonite (Hydrated Iron Oxide / Bog Iron)
FeO(OH)·nH2O
Mineral (Sedimentary context)
Jasper (likely Polychrome or Mookaite variants)
Silicon Dioxide (SiO2) with iron oxide and hydroxide inclusions
sedimentary (chemically precipitated)
Unidentified small mineral specimen
Undetermined from the image
mineral
Limonite (Iron Ore)
Hydrous Iron Oxide (goethite, lepidocrocite)
Mineral
Green Onyx (Banded Calcite)
Travertine (CaCO3 - Calcium Carbonate)
sedimentary
Likely ironstone pebble
Iron-rich concretion, probably goethite/limonite cementing sediment; exact identification is uncertain from the photograph
sedimentary
White/green translucent tumbled mineral fragment
Likely calcite (CaCO₃), possibly fluorite (CaF₂) or glass-like feldspar; visual identification is uncertain
mineral
Chert with Quartz Veining
Microcrystalline Silica (SiO2)
sedimentary
Banded Iron Formation
Banded Iron Formation (BIF)
sedimentary
Rounded beach pebble, likely fine-grained sandstone or siltstone
Indeterminate sedimentary lithic fragment; exact identification requires examination
sedimentary
Agate (Chalcedony)
Silicon Dioxide (SiO2)
mineral
Carnelian
Carnelian (Cryptocrystalline Quartz, SiO2)
mineral
Pink Dyed Agate
Silicon Dioxide (SiO2) with synthetic pigment
mineral
Satin Spar
Fibrous Gypsum (CaSO4·2H2O)
mineral
Vanadinite
Vanadinite (Pb5(VO4)3Cl)
mineral
Celestite (Celestine)
Celestine (Strontium Sulfate, SrSO4)
Mineral
Yellow Quartz (Citrine Quartz variety / Ferruginous Quartz)
Silicon Dioxide (SiO2) with iron inclusions
mineral
Green-gray stone pebble (not reliably identifiable from the image)
Undetermined; possibly a fine-grained sedimentary rock such as mudstone or siltstone
sedimentary
Chert (Limestone-based)
Silicon Dioxide (SiO2)
sedimentary
River Jasper
Silicon Dioxide (SiO2) with impurities
sedimentary
Turquoise
Turquoise - CuAl6(PO4)4(OH)8·4H2O
gemstone
Turquoise
CuAl6(PO4)4(OH)8·4H2O
mineral
Turquoise
Turquoise - CuAl6(PO4)4(OH)8·4H2O
mineral
Tumbled brown translucent mineral fragment
Indeterminate; possibly quartz/chalcedony or weathered feldspar
mineral
Small translucent mineral fragment, possibly calcite or quartz
Probable calcite (CaCO₃) or quartz (SiO₂); image resolution prevents confident separation
mineral
Moss Agate
Chalcedony (SiO2 with inclusions)
mineral
Vesicular basalt with secondary mineralization
Mafic volcanic rock, chiefly plagioclase and pyroxene, with iron oxides and likely zeolite/calcite infillings
igneous
Limonite (Ironstone Concretion)
Limonite (FeO(OH)·nH2O)
sedimentary
Chert with Calcite Veins
Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) intrusions
sedimentary
Quartz Geode with Iron Oxide
Silicon Dioxide (SiO2) with Hematite/Goethite coatings
mineral
Possible dark cobble or pebble
Unidentified rock; composition cannot be determined from the image
sedimentary
Calamites
Calamites (Pith cast fossil)
sedimentary
Limestone with Calcite Vug
Calcium Carbonate (CaCO3) in Sedimentary Matrix
sedimentary
Calcite with Quartz coating
Calcium Carbonate (CaCO3) with Silicon Dioxide (SiO2)
mineral
Unidentified polished stone fragments
Indeterminate; likely mixed lapidary specimens, possibly jasper, agate, or quartz-bearing rock
mineral
Unopened Geode
Geode (containing various mineralization like Quartz SiO2)
sedimentary
Iron-rich brown chert or weathered ironstone
Chert (microcrystalline quartz, SiO₂), possibly limonitic/goethitic ironstone
sedimentary