Moss Agate
Cryptocrystalline Quartz (SiO2 with manganese or iron oxide inclusions)
Category
Browse organic (biological organism) specimens identified by the Rock Identifier community.
Moss Agate
Cryptocrystalline Quartz (SiO2 with manganese or iron oxide inclusions)
Petrified Wood
Silicified Wood (SiO2)
Shale
Shale (fine-grained clastic sedimentary rock)
Chert
Chert (microcrystalline quartz, SiO2)
Fossilized Bone
Vertebrate fossil (mineralized bone)
Petrified Wood
Silicified Wood (Silicon Dioxide - SiO2)
Honey calcite (orange calcite)
Calcite, calcium carbonate (CaCO₃)
Moss Agate
SiO2 (Cryptocrystalline Quartz)
Weathered dark flint (chert) pebble
Microcrystalline quartz (SiO₂), commonly called flint or chert
Fossil Coral (Petoskey Stone / Rugose Coral)
Hexagonaria percarinata (or similar fossilized rugose/tabulate coral)
Petrified Wood
Silicified Wood (SiO2)
Rugose Coral (Horn Coral) Fossil
Order Rugosa (likely Grewingkia or Zaphrentis genus)
Fossil Coral
Rugosa or Tabulata coral fossil
Chert Nodule / Ironstone Concretion
Microcrystalline Quartz (SiO2) with Iron Oxides
Chert Nodules or Concretion
Cryptocrystalline Quartz (SiO2)
Amber (Tumbled/Polished)
Succinite (Fossilized Tree Resin)
Petrified Wood
Silicified Wood (SiO2)
Sandstone Chert Concretion
Silica-cemented Concretion (primarily SiO2)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide
Amber
Succinite
Sandstone with Vitrinite/Coal inclusions
Arenite with Carbonaceous inclusions
Chert / Flint (with Crinoid Stem Molds)
Microcrystalline Quartz (SiO2)
Amber
Succinite (specifically for Baltic Amber), Formula: C10H16O
Amber
Succinite (C10H16O)
Amber
Succinite (specifically for Baltic amber); approximate formula C10H16O
Chert (containing Fossil Mold)
Silicon dioxide (SiO2)
Moss Agate
Chalcedony (Silicon Dioxide - SiO2) with inclusions
Ferruginous Sandstone Concretion (Ironstone Phosphorite)
Ferruginous Sandstone (variable Fe-oxide/hydroxide composition)
Yellow Calcite
Calcium Carbonate (CaCO3)
Dyed Coral
Calcium carbonate (CaCO3) - Calcite or Aragonite with dye
Amber
Succinite (fossilized resin)
Amber (Burmite)
Fossilized tree resin (Succinite variant)
Amber
Succinite (Formula: C10H16O)
Amber
Succinite (a specific high-quality amber from the Baltic)
Amber (Butterscotch/Egg Yolk Variety)
Succinite (Approx. C10H16O)
Fossiliferous limestone (likely crinoidal or shell limestone)
Calcite-rich limestone; predominantly CaCO₃, with visible fossil fragments
Chalcedony / Agate with Botryoidal Quartz
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Fossilized Gastropod Shell
Gastropoda (Fossilized internal mold or shell body)
Limestone
Sedimentary rock primarily composed of Calcite (CaCO3)
Orange Calcite
Calcium Carbonate (CaCO3)
Black Flint
Chert (Microcrystalline Quartz, SiO2)