Amazonite
Triklinic Potassium Feldspar (KAlSi3O8)
Category
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
Amazonite
Triklinic Potassium Feldspar (KAlSi3O8)
Pink Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
Rhodochrosite with Pyrite and Quartz
Manganese Carbonate (MnCO3)
Chert (Flint Nodular)
Silicon Dioxide (SiO2)
Mixed Quartz Bracelet (Rose Quartz and Larimar-colored beads)
Silicon Dioxide (SiO2) with various inclusions
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Agate
Silicon Dioxide (Chalcedony), SiO2
Chert (Brown Variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert Nodule
Microcrystalline Quartz (SiO2)
Dyed Pink Quartzite (Jadeite Simulant)
Silicon Dioxide (SiO2) with organic dye
Red Jasper Pebble
Opaque microcrystalline Quartz (SiO2) with Iron Oxide
Fossilized Wood (Petrified Wood) and Associated Rocks
Silicified Wood / Xylopal
Dalmatian Stone
Dalmatian Jasper (Aplitic Rock)
Black Chert
Carbonaceous Chert (Silicon dioxide, SiO2)
Limestone (with Chert)
Calcium Carbonate (CaCO3) / Microcrystalline Quartz (SiO2)
Precious Red Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
Malachite
Copper carbonate hydroxide [Cu2CO3(OH)2]
Chert (Jasper/Agate variant)
Microcrystalline Quartz (SiO2)
Yellow Jasper
Chalcedony (Silicon Dioxide, SiO2) with iron oxide inclusions
Agatized Fossil (Druzy Agate)
Silicon Dioxide (SiO2) replacing organic matter
Gravel/Common Siltstone
Siltstone (fine-grained siliciclastic sedimentary rock)
Glauconitic Sandstone (Greensand)
Glauconitic Sandstone (Iron-potassium phyllosilicate mineral: (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Chert (often called Flint or Chalcedony Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Rhodonite
Rhodonite (Manganese Iron Magnesium Calcium Silicate) - (Mn,Fe,Mg,Ca)SiO3
Red Quartzite
Quartzite (SiO2)
Chert (and associated Sedimentary rocks)
Microcrystalline Silica (SiO2)
Limestone with Calcite Veining
Sedimentary Rock (Calcium Carbonate, CaCO3)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Sugilite
Sugilite (KNa2(Fe,Mn,Al)2Li3Si12O30)
Pyrite in Matrix (Quartz/Schist)
Iron Sulfide (FeS2)
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Orange Calcite
Calcium Carbonate (CaCO3)
Halite (Rock Salt)
Halite (NaCl)
Fossiliferous Limestone
Sedimentary Calcium Carbonate (CaCO3)
Jasper Conglomerate
Polymictic Conglomerate with Jasper and Quartz
Graywacke
Graywacke Sandstone (C6H10O5)x - predominantly quartz and feldspar
Iron Ore (Hematite/Goethite)
Ironstone (Fe2O3 / FeO(OH))
Sodalite
Na8(Al6Si6O24)Cl2
Fluorite
Calcium Fluoride (CaF2)
Agate Geode
Cryptocrystalline Quartz (SiO2)