Agate (Geode/Nodule)
Chalcedony (cryptocrystalline silica, SiO2)
Category
Browse organic (sedimentary context) specimens identified by the Rock Identifier community.
Agate (Geode/Nodule)
Chalcedony (cryptocrystalline silica, SiO2)
Petrified Wood
Silicified Wood (primarily Chalcedony or Quartz, SiO2)
Chert (Iron-stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Amber
Succinate (Fossilized Tree Resin)
Amber
Organic gemstone (Succinite is common if from the Baltic)
Baltic Amber
Succinite (Fossilized Tree Resin)
Petrified Wood
Silicified Wood (SiO2)
Fossilized Shark Tooth
Chondrichthyes (Class) fossil
Chert
Chert (Microcrystalline Quartz, SiO2)
Sandstone with Fossil Leaf Impression
Sedimentary rock (Sandstone/Siltstone matrix) with Carbonaceous film fossil
Chert (varieties include Flint and Mudstone)
Microcrystalline Silica (SiO2)
Fossilized Bone
Fossilized Vertebrate Bone (Per mineralized)
Petrified Wood
Silicified wood (principally SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Limestone with Iron Oxide Staining
Sedimentary Rock (Calcite, CaCO3)
Chert
Sedimentary Cryptocrystalline Quartz (SiO2)
Pink Opal
Hydrated silica (SiO2 "n H2O)
Coal
Anthracite or Bituminous Coal
Petrified Wood
Silicified Wood (primarily SiO2)
Amber
Succinite (Organic Mineraloid) - C10H16O
Fossilized Shark Tooth
Chondrichthyes (class)
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
Petrified Wood
Silicified Wood (mainly Quartz / SiO2)
Bivalve Fossil (Clam Stone)
Phylum Mollusca, Class Bivalvia
Chert (Flint)
Chert (Cryptocrystalline Silicon Dioxide, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert / Flint
Microcrystalline Quartz (SiO2)
Weathered flint or chert fragment
Microcrystalline quartz (SiO₂), likely chert/flint
Chalcedony / Agate with Botryoidal Quartz
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Moss-covered Rock Fragment
Weathered Rock Fragment with Epilithic Growth
Ironstone Concretion
Ironstone (Limonite/Goethite Concretion)
Red Moss Agate (Jasper)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Green Moss Agate
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
Chert (often called Jasper or River Siltstone)
Microcrystalline Quartz (SiO2)
Amber
Succinite (with approximate formula C10H16O)
Amber
Succinite
Sandstone with Quartz Crystal Infill
Quartz-cemented quartz arenite
Limestone
Calcium Carbonate (CaCO3)
Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Jasper
Agate/Jasper (Microcrystalline Quartz, SiO2)
Petrified Wood
Silicified Wood (SiO2)