Desert Varnish (on Sandstone)
Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)
sedimentary
Category
Mineral With Artificial Coating
Browse mineral with artificial coating specimens identified by the Rock Identifier community.
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Bumblebee Jasper
Carbonate-rich volcanic sediment with arsenic and sulfur inclusions
sedimentary
Yellow Jasper
SiO2 (Silicon Dioxide)
sedimentary
Dyed Agate
Microcrystalline Quartz (SiO2) with artificial pigment
sedimentary
Dyed Quartzite
Tumbled Metamorphosed Quartz (SiO2) with artificial pigment
metamorphic
Pyrite
Iron Disulfide (FeS2)
mineral
Amethyst
Amethyst (SiO₂)
Mineral
Peridot (likely, given the color and bead form)
Olivine, variety Peridot (Mg,Fe)2SiO4
Mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Agate (specifically, multi-colored or pastel-dyed agate)
Silicon dioxide (SiO2) - specifically, a cryptocrystalline variety of quartz known as Chalcedony, with banding classified as Agate. (If it were Fluorite, the chemical formula would be Calcium Fluoride - CaF2).
Mineral
Amethyst
SiO2 (Silicon Dioxide)
Mineral
Greenstone Porphyry
Altered Porphyritic Andesite/Basalt
igneous
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Diorite (Spotted or Dalmatian Stone effect)
Diorite (Intermediate Plutonic Rock)
igneous
Smoky Quartz
Quartz (SiO₂)
Mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Limonite (Iron Ore)
Limonite (an FeO(OH)·nH2O mineraloid, not a true mineral due to variable composition)
Mineral
Ironstone with Limonite/Goethite coating
Ferruginous Sedimentary Rock (contains Limonite FeO(OH)·nH2O)
sedimentary
Nephrite Jade
Nephrite
Mineral/Rock
Amethyst
SiO2 (Silicon Dioxide) - a variety of Quartz
Mineral
Sandstone Beach Pebble
Clastic Sedimentary Rock (primarily Quartz with Iron Oxide coating)
sedimentary
Citrine
Quartz (SiO2) - specifically, a variety of macrocrystalline quartz
mineral
Rainbow Hematite (Man-made/Treated)
Tumbled Hematite with Titanium/Anodized coating (Iron(III) oxide, Fe2O3)
mineral
Pink Dyed Agate
Silicon Dioxide (SiO2) with artificial pigment
sedimentary
Magnetic Hematite
Magnetized Hematite (an iron oxide mineral, Fe2O3, that has undergone magnetization)
Mineral
Spinosaurus fossil (permineralized bone)
Spinosaurus aegyptiacus (Calcium phosphate mineralized with silica/sediment)
sedimentary
Quartz Geode/Druzy Quartz
Quartz (SiO₂)
Mineral
Limonite (Iron Ore)
Hydrous Iron Oxide (goethite, lepidocrocite)
Mineral
Smoky Quartz
Quartz (SiO₂)
Mineral
Native Copper with Malachite/Oxide Coating
Native Copper (Cu)
mineral
Blue Lace Agate
Chalcedony (a form of Quartz) - SiO2
Mineral
Mica (Muscovite)
Muscovite, KAl2(AlSi3O10)(OH)2
Mineral
Granite
Phaneritic Plutonic Felsic Rock
igneous
Amethyst
Quartz variety; SiO2 (Silicon Dioxide)
Mineral
Garnet Beads
Garnet Group (complex nesosilicates, e.g., Almandine Fe3Al2(SiO4)3)
Mineral
Dyed Agate
Silicon Dioxide (SiO2) with artificial pigment
sedimentary
Blue Dyed Agate
Silicon Dioxide (SiO2) with artificial pigment
gemstone
Dyed Agate
Silicon Dioxide with artificial pigment (SiO2)
sedimentary
Dyed Pink Agate (or Dyed Quartzite)
Silicon dioxide (SiO2) with artificial pigment
sedimentary
Agate
Agate (a variety of Chalcedony, SiO2)
Mineral
Pearls
Aragonite (calcium carbonate) and Conchiolin
Mineraloid
Red Sandstone
Arenite (with Iron Oxide / Hematite), Formula: SiO2 (Quartz) + Fe2O3 (Hematite coating)
sedimentary