Pyrite
Iron Sulfide (FeS2)
Category
Browse mineral specimen specimens identified by the Rock Identifier community.
Pyrite
Iron Sulfide (FeS2)
Eagle Eye Stone (Green Tiger's Eye)
Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Concrete
Anthropogenic Sedimentary Rock (Hydrated Calcium Silicate)
Quartz (River Pebble)
Quartz (Silicon Dioxide, SiO2)
Beryl (likely Aquamarine) in matrix
Be3Al2(SiO3)6 (Beryllium Aluminum Silicate)
Granite (Dioritic or Hornblende-rich)
Phaneritic Plutonic Felsic to Intermediate Igneous Rock
Pyrite
Iron Disulfide (FeS2)
Blue Lace Agate
Silicon Dioxide (SiO₂)
Milk Quartz (Tumbled Pebble)
Quartz (Silicon Dioxide, SiO2)
Ferruginous Conglomerate (or Iron-Rich Concrete/Slag)
Clastic Sedimentary (Silicon Dioxide/Iron Oxide matrix)
Gneiss
Gneiss (High-grade regional metamorphic rock)
Chalcedony in Limestone Host Rock
Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)
Honey Calcite
Calcium Carbonate (CaCO3)
Staurolite (Fairy Stone)
Staurolite (Fe2+2Al9Si4O23(OH))
White Chalcedony (Agate)
Silicon Dioxide (SiO2)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3/FeO(OH)) inclusions
Mahogany Obsidian
Volcanic Glass (with inclusions of Magnetite or Hematite)
Limonitic Iron Ore / Goethite
Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Obsidian
Volcanic glass (no mineral formula due to amorphous structure, mostly SiO2)
Mookaite Jasper
Silicified Radiolarite (SiO2)
Dream Amethyst (Chevron Amethyst)
Silicon Dioxide with Iron impurities (SiO2)
Rose Quartz
Silicon Dioxide with traces of titanium, iron, or manganese (SiO2)
Smoky Quartz
Silicon dioxide with aluminum impurities (SiO2)
Sandstone (with Feldspathic/Arkose qualities)
Arenite (primarily SiO2 with KAlSi3O8 components)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Dendritic Jasper (River Stone)
Silicon Dioxide (SiO2) with Manganese/Iron Oxide inclusions
Zebra Jasper
Silicon Dioxide (SiO2) - Macro-crystalline Quartz/Chert with impurities
Petrified Wood
Silicified Wood (primarily SiO₂ - Silicon Dioxide)
Acicular Azurite (indicated by deep blue, fibrous/fuzzy appearance)
Azurite (Copper Carbonate Hydroxide) - Cu3(CO3)2(OH)2
Basalt with Quartz Veins
Basalt (complex silicate) with Quartz (SiO2) intrusions
Azurite and Malachite on Matrix
Azurite: Cu3(CO3)2(OH)2; Malachite: Cu2CO3(OH)2
Jasper with Agate and Quartz Inclusions
Silicon Dioxide (SiO2) - Chalcedony / Quartz aggregate
Fossilized Bone Fragment
Permineralized Vertebrate Bone (Hydrox yapatite replaced by Silica or Calcite)
Sandstone (likely Quartzose Sandstone with mineral staining)
Arenite (composed mainly of SiO2)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Dyed Agate Slice
Silicon Dioxide (SiO2) with artificial colorants
Banded Calcite (often sold as 'Mexican Onyx')
Calcite (Calcium Carbonate, CaCO3)
Ruby (Corundum)
Aluminum Oxide (Al2O3) with Chromium traces