Hematite
Iron(III) oxide (Fe2O3)
Category
Browse metamorphic or sedimentary depending on local grade specimens identified by the Rock Identifier community.
Hematite
Iron(III) oxide (Fe2O3)
Clear Quartz
Silicon Dioxide (SiO2)
Quartz (Milky and Bull Quartz)
Silicon Dioxide (SiO2)
Mixed Tumbled Stones Collection
Mixed Silicates and Carbonates (Quartz, Amorphous Silica, Carbonates)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Hematite
Iron(III) oxide (Fe2O3)
Pyrite
Iron Sulfide (FeS2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Amazonite
Amazonite (KAlSi3O8, a variety of Microcline)
Marble
Recrystallized Calcite / Dolomite (CaCO3)
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Yellow Aventurine (or Citrine-colored Quartz)
Silicon Dioxide (SiO2) with inclusions
Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image)
SiO₂ (silicon dioxide)
Chert
Chert (microcrystalline quartz)
Carnelian Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
Banded Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Green Jasper
Silicon Dioxide (SiO2) with impurities of iron(II) silicate
Petrified Wood
Silicified Wood (primarily SiO2)
Quartz Geode
Silicon Dioxide (SiO2) within a secondary sedimentary structure
Chert (Nodular or Massive Variety)
Cryptocrystalline Quartz (SiO2)
Fossil Shark Tooth (Sand Tiger or Mackerel Shark)
Carcharias sp. or Otodus sp. replaced by Hydroxylapatite/Calcium Carbonate
Yellow Jasper
Silicon Dioxide (SiO2) with impurities of Iron or Goethite
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (specifically Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossiliferous Limestone (Coquina / Shell Conglomerate)
Bioclastic Limestone (composed primarily of CaCO3)
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
Carnelian
Carnelian (SiO2 with Iron Oxide impurities)
Gossan (Iron Hat)
Limonitic Gossan (predominantly FeO(OH)·nH2O)
Quartzite with Sandstone/Iron staining
Metamorphic Quartzite (SiO2)
Quartz (Milky/Iron-stained)
Silicon Dioxide (SiO2)
Dendritic Agate
Silicon Dioxide with Manganese or Iron Oxide inclusions (SiO2 + Mn/Fe)
Limestone
Calcium Carbonate (CaCO3)
Unakite
Epidote-Feldspar rock
Chalcedony (Agate/Chert variety)
Silicon Dioxide (SiO₂)
Moss Agate
Silicon Dioxide with inclusions (SiO2 + impurities)
Turquoise (Green variety)
Hydrous phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O
Calcite
Calcium Carbonate (CaCO3)
Chert (Common Opal variant)
Silicon Dioxide (SiO2)
Ironstone (likely Ferruginous Siltstone/Sandstone)
Ferruginous sedimentary rock (FeOx-rich clastic)
Ironstone Concretion
Siderite or Hematite-bonded Concretion
Ironstone Concretion (Iron-rich Mudstone)
Siderite / Geothite concretion (FeCO3 / FeO(OH))
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 oxides)