Limonite (Iron Ore)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
mineral
Category
Mineral And Organic Gemstone
Browse mineral and organic gemstone specimens identified by the Rock Identifier community.
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Shale
Fissile Mudstone (Shale)
sedimentary
Black Jasper (Etched)
Silicon Dioxide (SiO2) with impurities
mineral
Chalcedony (Agatized Coral / Rough Chalcedony Node)
Silicon Dioxide (SiO2)
mineral
Sandstone (with potential fossil inclusions)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Jasper
Silicon Dioxide (SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2)
mineral
Petrified Wood
Silicon Dioxide (SiO2) - Calcified / Silicified Wood
sedimentary
Petrified Wood
Silicified Wood (SiO2)
fossil
Blue Topaz
Aluminum Silicate Fluoride Hydroxide Al2SiO4(F,OH)2
mineral
Chert / Jasper
Silicon Dioxide (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO₂)
sedimentary
Mixed Gemstone and Mineral Collection
Mixed Silica and Carbonate minerals (SiO2, CaSO4·2H2O, etc.)
mineral
Jasper
Microcrystalline Quartz (SiO2)
Sedimentary/Mineral
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Olivine (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4
Mineral
Moss Agate
Silicon Dioxide (SiO2) with inclusions
mineral
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxides
mineral
Almandine Garnet in Matrix
Almandine (Fe3Al2(SiO4)3)
metamorphic
Moss Agate
Chalcedony (Silicon Dioxide with inclusions) - SiO2
mineral
Chrysocolla
Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Hydrated Copper Phyllosilicate)
mineral
Granitic Pegmatite with Muscovite Mica
Pegmatite (containing KAl2(AlSi3O10)(OH)2)
igneous
Agatized Fossil (Druzy Agate)
Silicon Dioxide (SiO2) replacing organic matter
sedimentary
Jasper or Agate (Chalcedony)
Silicon Dioxide (SiO2) with impurities
sedimentary
Sandstone
Arenite (primarily composed of SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Septarian Nodule
Septarian Concretion
sedimentary
Green Moss Agate
Agate (Silicon Dioxide - SiO2 with inclusions of Manganese/Iron oxides)
mineral
Petrified Wood
Silicified Wood (SiO2 - Quartz/Chalcedony replacement)
Mineral / Fossil
Garnet in Matrix (Schist or Quartz)
Almandine Garnet, Fe3Al2(SiO4)3
metamorphic
Petrified Wood
Silicified Wood (primarily SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Fossilized Brain Coral
Diploria labyrinthiformis (Fossilized)
sedimentary
Chert (often called Flint)
Chert (Microcrystalline Silicon Dioxide, SiO2)
sedimentary
Pyrite on Limestone
Iron Disulfide (FeS2) in Calcium Carbonate (CaCO3) matrix
sedimentary (matrix) / mineral (inclusion)
White Topaz
Al2SiO4(F,OH)2
mineral
Zebra Marble
Metamorphosed Alabaster/Limestone (CaCO3)
metamorphic
Yellow Sapphire or Citrine
Al2O3 (Corundum) or SiO2 (Quartz)
mineral
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 cement)
sedimentary
Moonstone
Potassium Aluminum Silicate (KAlSi3O8)
mineral
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Chrysocolla in Cuprite (Sonoran Sunrise)
Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O) (Chrysocolla) and Cu2O (Cuprite)
mineral