Petrified Wood
Silicified Wood (SiO2)
fossil
Category
Organic Gemstone
Browse organic gemstone specimens identified by the Rock Identifier community.
Learn about Organic Gemstone in the encyclopedia
View all →
Chert Nodules in Limestone
Cryptocrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)
sedimentary
Druzy Chalcedony/Quartz on Fluorite core
Silicon Dioxide (SiO2) on Calcium Fluoride (CaF2)
mineral
Banded Chert
Cryptocrystalline Quartz (SiO2)
sedimentary
Fossiliferous Limestone
Calcium Carbonate (CaCO3)
sedimentary
Amber
Succinate (Fossilized Resin)
mineral
Petrified Wood
Silicified Wood (SiO2 - Quartz/Chalcendony replacing organic matter)
sedimentary
Fossil Shark Tooth
Carcharodon sp. (likely Otodus or similar Lamniformes order)
sedimentary
Siderite Concretion in Shale
Iron carbonate (FeCO3) in Mudstone/Shale matrix
sedimentary
Grass (Organic Matter/Soil)
Poaceae (family of monocotyledonous flowering plants)
Organic Materia (Not a rock or mineral)
Amber
Succinite (fossilized resin)
mineral
Amber
Fossilized Resin (C10H16O)
mineral
Amber
Succinite (specifically for Baltic amber); approximate formula C10H16O
Mineraloid
Amber
Succinite (C10H16O)
mineraloid
Glauconite (Greensand)
Glauconite (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2
sedimentary
Fossiliferous Limestone
Fossiliferous Limestone (containing bioclasts)
sedimentary
Amber
Succinate (Fossilized Tree Resin)
mineraloid
Potassium-Rich Silicate Clay (inferred from biological context)
Phyllosilicate group (likely Illite or Smectite within surrounding soil substrate)
mineral
Travertine
Travertine (a terrestrial form of Limestone, CaCO3)
sedimentary
Fossiliferous Limestone
Carbonate Rock (CaCO3 with organic inclusions)
sedimentary
Manganese Dendrite on Siltstone
Manganese Oxide (pyrolusite or psilomelane) Dendrites
mineral/sedimentary
Amber
Succinate (Fossilized Tree Resin)
fossil
Chert Concretion / Nodule
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz / Chalcedony: SiO2)
sedimentary
Coarse Sand or Fine Gravel
Detrital Sedimentary Fragments (mostly SiO2)
sedimentary
Limestone Pebble with Crinoid Fossil
Calcium Carbonate (CaCO3) - Fossiliferous Limestone
sedimentary
Fossiliferous Limestone
Fossiliferous Limestone (CaCO3)
sedimentary
Amber
Succinite
mineral
Fossiliferous Kalkstein (Marl/Sandstone)
Fossiliferous calcarenite/siltstone
sedimentary
Paper (Cellulose)
Cellulose (C6H10O5)n
Organic (Anthropogenic)
Moss Agate
SiO2
mineral
Chert (and Fossilized Brachiopod shell)
Sedimentary Cryptocrystalline Quartz (SiO2)
sedimentary
Knightia Fossil in Limestone
Knightia eocaena in micritic limestone
sedimentary
Manganese-coated Sandstone
Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)
sedimentary
Fossiliferous Limestone with Rugose Coral
Lithostrotionella (Limestone Matrix - CaCO3)
sedimentary
Pyrite
Pyrite (FeS2)
Mineral
Amber
Succinates (Fossilized Resin)
mineral
Glauconitic Sanstone (Glauconite)
Glauconite ((K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
Amber
Succinate (Fossilized Tree Resin)
mineraloid
Amber
Succinite (Fossilized Resin)
mineral
Sandstone Concretion
Limonitic Sandstone Concretion
sedimentary
Amber in Matrix
Succinite (Carbon-based organic polymer)
Organic (Sedimentary context)