Limonite Concretion
Limonite (Hydrated iron oxide) FeO(OH)·nH2O
Category
Browse sedimentary (secondary mineral) within igneous specimens identified by the Rock Identifier community.
Limonite Concretion
Limonite (Hydrated iron oxide) FeO(OH)·nH2O
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Amethyst
Silicon dioxide (SiO2) with iron impurities
Amethyst and Peridot
Amethyst (SiO2 with iron impurities) and Peridot ((Mg, Fe)2SiO4)
Copper Ore Specimen with Malachite
Cuprite, Malachite, and Limonite matrix
Quartz
Quartz (SiO₂)
Chert Breccia
Brecciated Chert (Microcrystalline Silica, SiO2)
Blue Topaz (facetted in jewelry)
Aluminum silicate fluoride hydroxide (Al2SiO4(F,OH)2)
Sandstone (Quartzose)
Arenite (SiO2)
Granite River Pebble
Granite
Quartz Crystal Cluster
Quartz (Silicon Dioxide, SiO2)
Basalt with Quartz Veining
Basalt (Mafic Extrusive Igneous Rock) with SiO2 (Silicon Dioxide) veins
Milky Quartz
Silicon Dioxide (SiO2)
Prehnite
Prehnite, Ca2Al2Si3O10(OH)2
Cannonball Concretion
Calcite-cemented Sandstone Concretion
Ironstone Nodules / Siderite Concretion
Siderite (FeCO3) / Ferruginous Septarian Concretion
Diamond
Carbon (C)
Celestite (Celestine)
Strontium sulfate (SrSO4)
Ironstone Concretion (Nutstone)
Ironstone (with High Limonite/Hematite Content)
Milky Quartz
Silicon Dioxide (SiO2)
Yellow Sapphire
Corundum (Al2O3:Fe)
Quartz Druzy on Matrix
Silicon Dioxide (SiO2)
Okenite
Okenite, Ca3Si6O15·6H2O
Turquoise (possible Howlite imitation)
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Variscite (or potentially a turquoise/variscite matrix cabochon, or an impression jasper)
AlPO4·2H2O (Variscite) or related phosphate/silicate material depending on exact composition
Howlite and Purpurite druzy
Calcium Borosilicate Hydroxide (Howlite) and Manganese Phosphate (Purpurite)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Orca Agate
Chalcedony (SiO2) with various inclusions
Celestine (or Celestite)
Strontium sulfate (SrSO4)
Moonstone
Orthoclase feldspar, (K,Na)AlSi3O8
Blue Apatite
Calcium Fluorophosphate - Ca5(PO4)3F
Labradorite
Plagioclase Feldspar (Na,Ca)(Al,Si)4O8
Eudialyte in Matrix
Na15Ca6(Fe,Mn)3Zr3(Si,Nb)(Si25O73)(O,OH,H2O)3(Cl,OH)2
Milky Quartz
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Citrine
Citrine (Silicon Dioxide, SiO2)
Amazonite
Microcline Feldspar (KAlSi3O8)
Sunstone
Plagioclase Feldspar (Na,Ca)(Al,Si)4O8
Chrysocolla in Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4' nH2O on Quartz/Feldspar matrix
Citrine (Yellow Quartz)
Silicon Dioxide (SiO2)
Quartz (River Cobble)
Silicon Dioxide (SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)