Mixed rounded river gravel
Polymictic alluvial gravel; likely mixtures of quartzite, granite, basalt, sandstone, and other silicate rocks
Category
Browse igneous and sedimentary mixture specimens identified by the Rock Identifier community.
Mixed rounded river gravel
Polymictic alluvial gravel; likely mixtures of quartzite, granite, basalt, sandstone, and other silicate rocks
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Blue Apatite
Apatite (Group), Ca5(PO4)3(F,Cl,OH)
Quartz Heart or Arrowhead Shape
Silicon Dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Quartz (Rose Quartz or Jasper variety)
Silicon Dioxide (SiO2)
Green Calcite
Calcium Carbonate (CaCO3)
Shale
Shale (clastic sedimentary rock)
Quartz
Silicon Dioxide (SiO2)
Apatite
Calcium phosphate fluoride/chloride, Ca5(PO4)3(F,Cl,OH)
Apatite
Calcium phosphate fluoride/chloride, Ca5(PO4)3(F,Cl,OH)
Bauxite
Bauxite (Mixture including Gibbsite Al(OH)3, Boehmite γ-AlO(OH), and Diaspore α-AlO(OH))
Bauxite
Bauxite (mixture including Gibbsite Al(OH)3, Boehmite γ-AlO(OH), and Diaspore α-AlO(OH))
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Quartz Pebble
Silicon Dioxide (SiO2)
Pyrite
Iron sulfide (FeS2)
Banded Iron Formation (BIF)
Banded Iron Formation
Quartz pebble
Silicon dioxide (SiO2)
Clear Quartz (Faceted) or Cubic Zirconia / Glass imitation
SiO2 (if Quartz), ZrO2 (if Cubic Zirconia)
Blue Apatite
Fluorapatite (Ca5(PO4)3(F,Cl,OH))
Blue Apatite
Ca5(PO4)3(F,Cl,OH)
Yellow Apatite
Fluorapatite (Ca5(PO4)3(F,Cl,OH))
Limonite
Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)
Alluvial stream gravel (mixed rock specimens)
Polymictic fluvial deposit; likely mixtures of quartzite, sandstone, shale, chert, basalt, and granite-derived minerals
Bauxite
Aluminum ore (mixture of gibbsite Al(OH)3, boehmite γ-AlO(OH), and diaspore α-AlO(OH))
Milky Quartz
Quartz (SiO2)
Pyrite
Iron Sulfide (FeS2)
Magnetite (Iron Ore)
Magnetite (Fe3O4)
Magnetite (potentially Hematite)
Magnetite (Fe₃O₄)
Banded Gneiss
Gneiss
Feldspar
Feldspar (Orthoclase/Microcline)
Pyrite Nodules / Weathered Pyrite
Iron Sulfide (FeS2)
Blue Apatite
Ca5(PO4)3(F,Cl,OH)
Clear Quartz
Silicon Dioxide (SiO2)
Chalcopyrite
Copper Iron Sulfide (CuFeS2)
Quartz
Silicon Dioxide (SiO2)
Diorite (Dalmatian Stone)
Phaneritic Plutonic Diorite
Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)
Chalcedony (SiO₂)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz vein fragment
Quartz, silicon dioxide (SiO₂), likely milky to translucent quartz with iron-oxide or clay inclusions