Petrified Wood
Silicified Wood (SiO2 as Quartz/Chert/Chalcedony)
Category
Browse organic mineral specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (SiO2 as Quartz/Chert/Chalcedony)
Pyrite in Shale
Iron Sulfide (FeS2) in Sedimentary Matrix
Sandstone (Weathered Coastal Boulder)
Arenite (composed primarily of SiO2)
Moss Agate
Silicon Dioxide with inclusions (SiO2 + impurities)
Pyrite
Iron Sulfide (FeS2)
Petrified Wood
Silicified wood (Quartz, Chalcedony, or Opal)
Pearl
Organic gemstone (Calcium carbonate / CaCO3 + Conchiolin)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide
Chert (with Quartz vein/coating)
Microcrystalline Quartz (SiO2)
Fossilized Crab Carapace (Concretion)
Decapoda (fossil), typically preserved in calcite or siderite concretion
Moqui Marbles
Iron Oxide Concretion (Hematite/Goethite)
Petrified Wood
Silicified wood (primarily SiO2)
Sandstone Chert Concretion
Silica-cemented Concretion (primarily SiO2)
Chert (often called Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sandstone Pebble
Arenite (primarily SiO2)
Amber
Succinite (with formula approximately C10H16O)
Banded Agate (specifically Moss Agate or Plume Agate variety)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Petrified Wood
Silicified Wood (SiO2)
Chert (Mudstone)
Microcrystalline Quartz (SiO2)
Tufa (Limestone)
Calcareous Tufa (CaCO3)
Amber Inlay Jewelry
Fossilized Resin (C10H16O)
Chert (with Limestone matrix)
Silicon dioxide (SiO2)
Petrified Wood
Silicified wood (Quartz/Chalcedony/Opal replacing organic matter)
Ferruginous Sandstone (with possible trace fossils)
Arenite with Iron-Oxide Cement (SiO2 with Fe2O3)
Chert (containing Iron Oxide)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Flint/Chalcedony)
Microcrystalline Quartz (SiO2)
Chert (often called Jasper in this color variety)
Microcrystalline Quartz (SiO2)
Chert / Flint
Microcrystalline or cryptocrystalline quartz (SiO2)
Green Sandstone
Glauconitic Sandstone
Fossilized Fish Skeleton in Matrix
Vertebrata (Class: Actinopterygii), typically found in limestone or shale matrices
Petrified Dinosaur Bone (Gembone)
Agatized Dinosaur Bone
Jasper
Silicon dioxide (SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified wood (Quartz, SiO2)
Chert with Quartz/Calcite Vein
Microcrystalline Silica (SiO2)
Pearl
Aragonite / Calcium Carbonate (CaCO3)
Pyrite Geode (Sparkling Druzy)
Iron Sulfide (FeS2) in Sedimentary Nodule
Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Amber
Succinite (specifically for Baltic amber); C10H16O (Variable organic compound)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Pearl
Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3