Garnet (likely Almandine or Pyrope)
Garnet Group (e.g., Almandine: Fe3Al2(SiO4)3; Pyrope: Mg3Al2(SiO4)3)
Category
Browse sedimentary (with some aspects of mineral replacement) specimens identified by the Rock Identifier community.
Garnet (likely Almandine or Pyrope)
Garnet Group (e.g., Almandine: Fe3Al2(SiO4)3; Pyrope: Mg3Al2(SiO4)3)
Satin Spar Selenite
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Peridot (Olivine)
Olivine ((Mg,Fe)2SiO4)
Sunstone and Green Aventurine
Sunstone: (Ca,Na)[(Al,Si)2Si2O8] (Plagioclase Feldspar Group); Green Aventurine: SiO2 (Quartz)
Barite Rose on Marcasite
Barium Sulfate (BaSO4) on Iron Sulfide (FeS2)
Topaz
Topaz (Al2SiO4(F,OH)2)
Fish Fossil in Limestone
Lycoptera (likely) in Micritic Limestone
Ferruginous Sandstone (River Pebble)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 cement)
Limonite (Iron Stone Concretion)
Limonite (Hydrous Iron Oxide) - FeO(OH)·nH2O
Fluorite with Quartz coating
Calcium Fluoride (CaF2) with Silicon Dioxide (SiO2)
Brown Sandstone
Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)
Sandstone (likely Arkosic or Lithic Sandstone)
Clastic Sedimentary Rock (SiO2 with assorted minerals)
Jasper
Jasper (Silicon Dioxide, SiO2)
Sodalite
Sodalite - Na8(Al6Si6O24)Cl2
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Magnetite
Magnetite (Fe3O4)
Quartz Geode
Silicon Dioxide (SiO2)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
Quartz Geode
Silicon Dioxide (SiO2)
Satin Spar (often sold as Selenite)
Gypsum (CaSO4·2H2O)
Ironstone (likely Limonite or Goethite nodule)
Hydrothermally altered Ferric Hydroxide (FeO(OH)·nH2O)
Ironstone Concretions (Ironstone)
Ferruginous Sandstone or Siltstone (Fe2O3)
Limonite with Hematite
Limonite (FeO(OH)·nH2O) and Hematite (Fe2O3)
Shale
Shale (fine-grained clastic sedimentary rock)
Emerald
Beryl (Be3Al2Si6O18), specifically the green variety colored by chromium or vanadium
Sulfur (on Matrix)
Native Sulfur (S8)
Quartz Geode
Silicon Dioxide (SiO2) within a geode
Quartz Geode
Silicon Dioxide (SiO2)
Satin Spar (Selenite)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Talc
Talc (Mg₃Si₄O₁₀(OH)₂)
Dendritic Agate or Manganese Nodule in Chert/Limestone
Silicon Dioxide (SiO2) with Manganese Oxide (MnO2) inclusions
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
Sandstone (Quartz-rich)
Arenite (SiO2)
Sandstone Concretion
Sedimentary concretion
Basalt
Basalt (Mafic volcanic rock)
Limonite (often after Hematite or Goethite)
Limonite (FeO(OH)·nH2O)
Shale
Shale
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
Sandstone
Arenite
Quartz Geode
Silicon dioxide (SiO2)
Brecciated Chert
Sedimentary Chert (SiO2) with Calc-Silicate mineralization
Ruby
Corundum (Al₂O₃) with Chromium (Cr)