Limonite Concretion
Limonite (FeO(OH)·nH2O)
sedimentary
Category
Mineral On Sedimentary
Browse mineral on sedimentary specimens identified by the Rock Identifier community.
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Satin Spar (Gypsum)
Hydrous Calcium Sulfate (CaSO4·2H2O)
mineral
Turquoise-look beads, likely dyed howlite or magnesite
Often dyed CaCO₃ (howlite/magnesite), rather than natural turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O
mineral
Satin Spar (Selenite)
Gypsum (CaSO4·2H2O)
mineral
Ironstone Concretion / Limonite Node
Goethite / Limonite (FeO(OH)·nH2O)
sedimentary
Limonite Concretion
Goethite-Limonite (FeO(OH)·nH2O)
sedimentary
Selenite (satin spar gypsum)
Gypsum, CaSO₄·2H₂O
mineral
Dendritic Jasper
SiO2 (Microcrystalline Quartz)
mineral
Ironstone Concretion (Limonite/Goethite)
Ironstone (composed primarily of Goethite FeO(OH) and Limonite)
sedimentary
Pyrite
Iron Disulfide (FeS2)
mineral
Carnelian
Carnelian (SiO2 with Iron Oxide impurities)
mineral
Gypsum (Selenite crystals in Halite/Clay matrix)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Ironstone Concretion
Ironstone (primarily Siderite or Limonite / Goethite, FeO(OH)·nH2O)
sedimentary
Satin Spar (often marketed as Selenite)
Fibrous Gypsum (CaSO4·2H2O)
mineral
Fossilized Blastoid (Sea Bud)
Pentremites sp. (Echinodermata, Blastoidea)
fossil
Chert (Lithic flake / Arrowhead fragment)
Microcrystalline Quartz (SiO2)
sedimentary
Possible fossilized shell or coral fragment
Indeterminate biogenic carbonate, likely calcite (CaCO₃)
fossil
Ferruginous Quartz (Carnelian-tinted Quartz)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
mineral
Ironstone Concretion / Limonite Specimen
Goethite and Limonite (Hydrous Iron Oxides)
sedimentary
Satin Spar (commercially called Selenite)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
mineral
Ironstone Concretion / Limonite
Goethite and Limonite (FeO(OH)·nH2O)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Orange Satin Spar (Satin Spar Selenite)
Satin Spar - Hydrous Calcium Sulfate (CaSO4·2H2O)
mineral
Ironstone Concretion (Limonite/Hematite Nodules)
Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)
sedimentary
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Hematite/Goethite inclusions
mineral
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Red Jasper
Red Jasper (variety of Chalcedony, SiO₂)
Mineral
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Mineral
Quartz on Limestone
Silicon Dioxide (SiO2) on Calcium Carbonate (CaCO3)
Mineral on Sedimentary
Quartz (Rock Crystal)
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Calcite
Calcite (Calcium Carbonate, CaCO3)
mineral
Pyrite
Iron Pyrite (FeS2)
mineral
Yellow Chalcedony
Chalcedony (a cryptocrystalline variety of Quartz, SiO₂)
Mineral
Clear Quartz (or Rock Crystal)
Quartz (SiO₂)
Mineral
Calcite
Calcite (Mineral, Calcium Carbonate - CaCO3)
Mineral
Quartz, Sandstone, and Siltstone specimens
Silicon Dioxide (SiO2) and Clastic Sedimentary Rocks
mineral and sedimentary
Quartz (White Pebble) and Sandstone (Brown/Tan Fragments)
Silicon Dioxide (SiO2) for the white pebble
mineral and sedimentary
Pyrite
Pyrite (Iron sulfide, FeS₂)
mineral
Larimar and Fossil Coral
Pectolite (NaCa2Si3O8(OH)) and Hexagonaria/Petoskey Stone
mineral and sedimentary
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Druzy Quartz on Matrix (likely Limestone or Sandstone)
Silicon Dioxide (SiO2) with various trace impurities
Mineral on Sedimentary Rock