Blue Apatite
Fluorapatite / Chlorapatite [Ca5(PO4)3(F,Cl,OH)]
Category
Browse man made byproduct (often mistaken for obsidian or emerald) specimens identified by the Rock Identifier community.
Blue Apatite
Fluorapatite / Chlorapatite [Ca5(PO4)3(F,Cl,OH)]
Red Sandstone
Arenite (Ferruginous Sandstone)
Scoria
Vesicular Basalt / Scoriaceous Basalt
Blue Quartzite (Aventurine)
Quartzite (primarily SiO2) with inclusions of Dumortierite or Magnesio-riebeckite
Zircon
Zircon (ZrSiO4)
Quartzite
Metamorphic Rock (Mainly SiO2)
Quartz (likely Yellow/Orange variety, possibly Citrine or Chalcedony with iron staining)
Quartz (SiO₂)
Sandstone (likely River-tumbled Picture Sandstone)
Arenite (predominantly SiO2 with iron oxide impurities)
Sandstone (Banded)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
Vesicular Basalt
Extrusive Mafic Igneous Rock (Vesicular Basalt)
Banded Calcite or Travertine
Calcium Carbonate (CaCO3)
Golden Sheen Obsidian
Obsidian (volcanic glass) with inclusions of gas bubbles and mineral crystals (e.g., hematite, magnetite) causing the sheen
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Sandstone (specifically an Iron-Concretion)
Arenite with Iron Oxide (Limonite/Goethite) cementation
Pegmatite (likely Granitic Pegmatite)
Pegmatite (a coarse-grained igneous rock, often with granitic composition)
Ironstone Concretion / Goethite Nodules
Ironstone (composed primarily of Goethite FeO(OH) and Limonite)
Smoky Quartz
SiO2 (Silicon Dioxide)
Banded Chert
Chert (a microcrystalline variety of quartz, SiO2 with minor impurities)
Chert (Flint)
Chert (predominantly SiO₂ - silicon dioxide)
Quartzite
Quartzite (primarily composed of SiO O₂)
Limonite (Iron Ore)
Hydrous Iron Oxide (goethite, lepidocrocite)
Sandstone Concretion
Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)
Chert (Quartz Variety)
Chert (Silicon Dioxide, SiO2)
Pyrite
Pyrite (Iron Disulfide), FeS2
BROWN GRANITE (likely 'Tan Brown' or similar)
Granite (specifically a variety rich in orthoclase feldspar, often with biotite and possibly hornblende)
Granite
Granite (a plutonic rock)
Nephrite Jade
Nephrite
Ferruginous Sandstone
Sandstone, Iron-rich
Jade (likely Nephrite or Jadeite)
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (Na(Al,Fe3+)Si2O6)
Emerald
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
Granite
Granite (a common rock name, not a single mineral species, composed primarily of quartz, feldspar, and mica/amphibole)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
Obsidian
Volcanic glass
Obsidian
Volcanic Glass (SiO2)
N/A - Non-Geological Item
Peridot
Olivine ((Mg, Fe)2SiO4)
Turquoise
Turquoise (Hydrated copper aluminum phosphate, CuAl6(PO4)4(OH)8·4H2O)
Granite River Rock
Phaneritic Felsic Igneous Rock (Granite)
Quartz
Quartz (SiO₂)
Slag (Industrial Glass Slag)
Amorphous Silicate Glass (often containing Al, Ca, Mg, and Ti oxides)
Obsidian
Volcanic Glass (SiO2 + impurities)
Peridot
Olivine (Magnesium Iron Silicate), (Mg, Fe)2SiO4