Placer Gold Nugget
Native Gold (Au)
Category
Browse synthetic or natural fiber specimens identified by the Rock Identifier community.
Placer Gold Nugget
Native Gold (Au)
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Diamond
Native Carbon (C)
Granite
Granite (Felsic Plutonic Rock)
Magnetite
Magnetite (Iron(II,III) oxide, Fe3O4)
Granite
Phaneritic Igneous Rock (composed primarily of Quartz SiO2, Alkali Feldspar, and Plagioclase)
Travertine (Tufa)
Terrestrial Sedimentary Limestone (CaCO3)
Mahogany Obsidian
Volcanic Glass with Hematite inclusions (SiO2)
Zinc Alloy (Silver-plated)
Zinc Alloy Casting (Zn-Al-Mg-Cu)
Smoky Quartz
Silicon Dioxide (SiO2)
Yellow Quartz (Citrine Quartz)
Silicon Dioxide (SiO2)
Dream Amethyst (Chevron Amethyst)
Silicon Dioxide (SiO2) with impurities of Iron (Fe3+)
Dream Amethyst (Chevron Amethyst)
Silicon Dioxide (SiO2) with iron impurities
Red Howlite (Dyed)
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5) with Red Dye
Jasper and Yellow Chert (Tumbled)
Microcrystalline Quartz (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Peacock Ore
Bornite (Cu5FeS4)
Gold Nugget
Native Gold (Au)
Obsidian
Volcanic Glass (SiO2 - Silicon Dioxide with impurities)
Coquina
Biogenic Limestone (Calcite, CaCO3)
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
Bornite (Peacock Ore)
Bornite (Cu5FeS4)
Sandstone (likely Siltstone or fine-grained Sandstone)
Sedimentary Rock (Clastic)
Porphyry
Porphyritic Andesite/Basalt
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Black Onyx (Tumbled)
Silicon Dioxide (SiO2)
Quartz (Water-worn pebble)
Silicon Dioxide (SiO2)
Emerald in Matrix (Quartz/Schist)
Beryl (Be₃Al₂Si₆O₁₈) with Chromium/Vanadium impurities
Rough Ruby (Corundum) in Zoisite Matrix
Al2O3 (Aluminum Oxide) with Ca2Al3(SiO4)3(OH)
Sandstone (Quartzite-rich)
Clastic Sedimentary Rock (primarily SiO2)
Rough Diamond
Carbon (C)
Chalcedony (Smoky Quartz or Agate nodule fragment)
Silicon Dioxide (SiO2)
Pink Granite
Phaneritic Felsic Intrusive Igneous Rock
Amethyst
SiO2 (Silicon Dioxide with iron impurities)
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions (Quartzite)
Jasper with Quartz Veining
Silicon Dioxide (SiO2) with impurities
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Emerald
Beryl (Be3Al2(SiO3)6) with trace Chromium/Vanadium
Magnetite
Magnetite (Fe3O4)
Green Aventurine
Aventurine (Silicon Dioxide with Fuchsite inclusions - SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
Pink Tourmaline in Quartz Matrix
Elbaite (Na(Li,Al)3Al6(Si6O18)(BO3)3(OH)4) in Quartz (SiO2)