Fossilized Bone Fragment
Permineralized Vertebrate Bone (Hydrox yapatite replaced by Silica or Calcite)
sedimentary
Category
Mineral, Often A Rock Given Its Aggregate Nature
Browse mineral, often a rock given its aggregate nature specimens identified by the Rock Identifier community.
Quartzite River Rock
Quartzite (primarily SiO2)
metamorphic
Basalt
Basalt
Igneous
Pyrite in Shale
Iron Sulfide (FeS2)
mineral
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Mineral
Slag
Glassy silicate byproduct (anthropogenic material)
industrial byproduct
Basalt with Plagioclase Phenocrysts
Porphyritic Basalt
igneous
Quartz Druzy on Agate (River Cobble)
Silicon Dioxide (SiO2)
Mineral / Sedimentary (often associated with volcanic hosts)
Red Jasper
Jasper (Silicon Dioxide, SiO2 with Iron Oxide impurities)
sedimentary
Quartz (River Pebble)
Quartz (Silicon Dioxide - SiO2)
mineral
Shale
Shale
sedimentary
Puddingstone
Conglomerate (specifically a type of jasper conglomerate or quartz conglomerate)
Sedimentary
Granite
Plutonic felsic igneous rock
igneous
Agate Geode
Silicon Dioxide (SiO2) - Chalcedony / Quartz Variety
Mineral
Schist
Mica Schist (Medium-grade Metamorphic Rock)
Metamorphic
Blue Dyed Agate Geode
Chalcedony (cryptocrystalline Quartz), SiO2
mineral
Blue Lace Agate (Polished Point)
Silicon Dioxide (SiO2) - Variety of Chalcedony
mineral
Red Jasper
Jasper (Silicon Dioxide with Iron Oxide impurities), formula: SiO2
mineral
Crushed Rock (Basalt)
Basalt (Aphanitic Mafic Igneous Rock)
Igneous
Iron-stained Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
mineral
Scoria
Scoria (a vesicular basalt or andesite)
igneous
Moonstone
Orthoclase Feldspar (KAlSi3O8)
Mineral
Gold Nugget
Native Gold (Au)
mineral
Basalt Pebble
Extrusive Mafic Igneous Rock
igneous
Red Jasper
Jasper (Silicon Dioxide, SiO2 with Fe2O3 inclusions)
mineral
Travertine (Tufa)
Chemical Sedimentary Limestone (CaCO3)
sedimentary
Wishing Stone with Quartz Vein
Hydrothermal Quartz Vein in Metasedimentary Matrix (primarily SiO2)
metamorphic
Dyed Agate Slice
Silicon Dioxide (SiO2) with artificial colorants
Mineral (variety of Chalcedony)
Dyed Agate
Silicon Dioxide (SiO2) - variety Chalcedony
mineral
Greenschist with Quartz Veining
Greenschist (commonly containing Chlorite, Actinolite, and Epidote)
metamorphic
Dendrite (Manganese Oxide Dendrites)
Psilomelane or Pyrolusite on Matrix (typically MnO2)
mineral
Chrysoprase
Chalcedony (cryptocrystalline SiO2 variety)
Mineral
Yellow Jasper
Silicon Dioxide (SiO2) with hydrated iron oxide impurities (Goethite)
Mineral-based Sedimentary/Silica
Picture Jasper
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper variety)
Chert (SiO2)
sedimentary
Travertine
Travertine (CaCO3 - Calcium Carbonate)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Diamond
Diamond (carbon allotrope), C (chemical formula)
Mineral
Chrysoprase
Chalcedony (cryptocrystalline quartz) with nickel inclusions; SiO2
Mineral
Dragon Vein Agate
Chalcedony (Quartz) - SiO2
mineral
Sandstone
Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)
Sedimentary
Sandstone (Calcareous Sandstone)
Calcareous Sandstone (primarily SiO2 with CaCO3 cement)
sedimentary