Olivine (Peridot when gem-quality)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Category
Browse sedimentary (biogenic sediment or biological remain) specimens identified by the Rock Identifier community.
Olivine (Peridot when gem-quality)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Graphite
Graphite (C)
Chert (specifically Flint or Jasper variant)
Silicon Dioxide (SiO2)
Quartz on Sandstone
Silicon Dioxide (SiO2) in Lithic Sandstone
Quartzite
Quartzite (primarily SiO2)
Green Jasper
Silicon Dioxide (SiO2) with impurities
Pyrite in Quartzite/Graphite Matrix
Iron Sulfide (FeS2)
Chalcedony (Quartz variety)
Silicon Dioxide (SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with iron inclusions
Quartz (Milky/Smoky variety)
Silicon Dioxide (SiO2)
Quartz (Milky/Common Quartz)
Silicon Dioxide (SiO2)
Jasper
Silicon Dioxide (SiO2) with impurities
Sand Dollar Fossil
Echinoidea (Clypeasteroida)
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Limonite Concretion
Limonite (Hydrated Iron Oxide) FeO(OH)·nH2O
Red Jasper (possibly Red Coral or dyed Howlite)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Gold Nugget
Native Gold (Au)
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2)
Sandstone
Arenite (SiO2 primarily)
Limestone (specifically Tufa or Travertine)
Calcium Carbonate (CaCO3)
Sandstone
Arenite (primarily SiO2)
Chert / Flint
Microcrystalline or cryptocrystalline quartz (SiO2)
Geode (unopened nodule)
Silicon Dioxide (SiO2) Nodule
Brown Agate
Silicon Dioxide (SiO2)
Quartz (Smoky/Grey variety)
Silicon Dioxide (SiO2)
Mica Schist (with Muscovite)
Muscovite/Quartz Schist (KAl2(AlSi3O10)(OH)2)
Brown Agate
Silicon Dioxide (SiO2)
Ruby in Zoisite
Anyolite (combination of Ca2Al3(SiO4)3(OH) and Al2O3:Cr)
Blue Chalcedony
Cryptocrystalline Quartz (SiO2)
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Garnet (Almandine)
Almandine (Fe3Al2(SiO4)3)
Quartz (Iron-stained or Milky)
Silicon Dioxide (SiO2)
Carnelian
Carnelian (SiO2)
Chert / Jasper
Microcrystalline Quartz (SiO2)
Halite (Rock Salt)
Halite (Sodium Chloride, NaCl)
Jasper Breccia
Silicon Dioxide (SiO2) with impurities
Jasper with Iron Staining
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Limonite/Hematite Ironstone
Goethite-rich Ironstone (FeO(OH) · nH2O)
Orange Calcite
Calcium Carbonate (CaCO3)
Gneiss
Gneiss (High-grade metamorphic rock)
Milky Quartz
Silicon Dioxide (SiO2)