Sandstone Concretion
Arenaceous concretion (primarily SiO2 with Fe2O3 staining)
Category
Browse organic mineraloid specimens identified by the Rock Identifier community.
Sandstone Concretion
Arenaceous concretion (primarily SiO2 with Fe2O3 staining)
Black Pearl (Tahitian-style Cultured Pearl)
Calcium Carbonate (Aragonite) with Conchiolin (CaCO3)
Calligraphy Stone
Mariam Jasper (Fossiliferous Limestone with Hematite and Iron)
Green Moss Agate / Jasper
Silicon Dioxide (SiO2) - Microcrystalline Quartz with Iron and Manganese inclusions
Chert (Arrowhead Preform)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Amber
Succinite (specifically for Baltic amber); chemical formula approx. C10H16O
Shale
Shale (comprised mostly of clay minerals and quartz)
Shale
Fissile Mudstone (Shale)
Moss Agate
Chalcedony (Silicon Dioxide / SiO2)
Precious Red Coral
Corallium rubrum / Corallium japonicum
Moss Agate
Silicon Dioxide with inclusions (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (with Limestone matrix)
Silicon dioxide (SiO2)
Chert / Flint
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)
Pearl
Calcium Carbonate (primarily Aragonite and Calcite), CaCO3
Chert (including Flint and Jasper variants)
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)
Chert (Jasper)
Silicon dioxide (SiO2)
Chert (Black Chert / Flint)
Silicon Dioxide (SiO2)
Chert (often called Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
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)
Chert (Black Chert/Flint)
Silicon Dioxide (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)