Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2 with chlorite inclusions)
Category
Browse organic (mineraloid) specimens identified by the Rock Identifier community.
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2 with chlorite inclusions)
Petrified Wood
Silicified Wood (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
Petrified Wood
Silicified Wood (SiO2)
Moss Agate
Silicon Dioxide (SiO2) with Chlorite/Oxide inclusions
Chert (specifically Flint or Dark Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Shell Cameo (Sardonyx Shell)
Cassis madagascariensis (Sardonyx shell)
Amber
Succinite (C10H16O)
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)
Dendritic Agate
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
Amber
Succinates (fossilized tree resin), approximately C10H16O
Glauconitic Sandstone (Greensand)
Glauconitic Quartz Arenite (containing Glauconite, (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Coquina or Fossiliferous Limestone
Fossiliferous Calcarenite (CaCO3)
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2)
Pink Opal
Hydrated silica (SiO2 "n H2O)
Green Moss Agate
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
Red Moss Agate (Jasper)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Chert (often called Jasper or River Siltstone)
Microcrystalline Quartz (SiO2)
Tree Agate
Silicon Dioxide (SiO2) with Dendritic Inclusions
Black Freshwater Pearls
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Green Moss Agate
Agate (Silicon Dioxide - SiO2 with inclusions of Manganese/Iron oxides)
Chalk
Calcium Carbonate (CaCO3)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
Fossiliferous Limestone
Biogenic Limestone (CaCO3)
Chert
Microcrystalline Quartz (SiO2)
Chert (Iron-Stained)
Chert (Silicon Dioxide, SiO2)
Chert (Basanite / Jasperoid)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Chert (Silicon Dioxide, SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (often called Jasper or River Pebble)
Microcrystalline Quartz (SiO2)
Glauconite Sandstone
Glauconitic Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with fossil inclusions
Chert (var. Jasper)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (Flint Nodules)
Cryptocrystalline Quartz (SiO2)
Blue Apatite
Calcium Phosphate (Ca5(PO4)3(F,Cl,OH))