Moss Agate
Chalcedony (Silicon Dioxide / SiO2)
Category
Browse organic gemstone specimens identified by the Rock Identifier community.
Moss Agate
Chalcedony (Silicon Dioxide / SiO2)
Moss Agate
Silicon Dioxide with inclusions (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Amber / Copal
Fossilized Tree Resin (Succinate)
Chert (with Limestone matrix)
Silicon dioxide (SiO2)
Chert (Jasper variation)
Chert (Microcrystalline Silicon Dioxide, SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2)
Glauconitic Sandstone (Greensand)
Glauconitic Sandstone (Iron-potassium phyllosilicate mineral: (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Chert (Flint)
Chert (SiO2)
Chert (and Chalcedony)
Silicon Dioxide (SiO2)
Chert (Beach Pebble)
Microcrystalline Quartz (SiO2)
Chert (often called Flint in various colors)
Silicon Dioxide (SiO2)
Chert (often called Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Graphite
Graphite (Native Carbon), Formula: C
Graphite
Graphite (Carbon, C)
Micro-crystalline Quartz Pebble (Chert)
Silicon dioxide (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Fossil Coral
Cnidaria Anthozoa (Fossilized)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Ironstone Concretion (Limonite/Goethite)
Iron oxide concretion (contains FeO(OH)·nH2O)
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxides
Moss Agate
Silicon Dioxide (SiO2) with Chlorite/Oxide inclusions
Petrified Wood
Silicified Wood (SiO2)
Lemon (Mock specimen mimicking Citrine/Sulfur)
Citrus x limon
Fossiliferous Limestone with Rugose Coral
Calcite (CaCO3) matrix containing Rugosa (order of extinct solitary and colonial corals)
Fossiliferous Limestone (Coquina / Shell Limestone)
Bioclastic Limestone (CaCO3)
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
Petrified Wood
Silicified Wood (primarily Silicon Dioxide, SiO2)
Chert (varieties include Flint and Jasper)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
Chert (specifically Gray/Black Chert)
Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)
Moss Agate
Chalcedony (SiO2) with dendritic inclusions of Manganese or Iron oxide
Shale
Shale (Sedimentary rock composed of mud/clay minerals)
Glauconitic Sandstone (Greensand)
Glauconitic Quartz Arenite (containing Glauconite, (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Chert (specifically Flint or Dark Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variant)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Glauconitic Sandstone
Glauconitic Sandstone with high Glauconite concentration ((K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Chert (Nodule)
Microcrystalline quartz (SiO2)
Chert (and Flint)
Chert (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Jasper
Silicon dioxide (SiO2) with impurities