Bituminous Coal (with Anthracite or Vitrinite inclusion)
Organic-rich Sedimentary Rock (Carboniferous classification)
Category
Browse organic (paper and cellulose) specimens identified by the Rock Identifier community.
Bituminous Coal (with Anthracite or Vitrinite inclusion)
Organic-rich Sedimentary Rock (Carboniferous classification)
Moss Agate (Crescent Moon Shape)
Silicon Dioxide (SiO2) with iron/manganese inclusions
Chert (Flint with Iron Staining)
Silicon Dioxide (SiO2)
Pink Opal
Hydrated Silica (SiO2·nH2O)
Chert (Flint)
Silicon Dioxide (SiO2)
Black Dolomite
Bituminous Dolomite (CaMg(CO3)2)
Chert (Nodule)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (variations include Flint or Jasper)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (specifically Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Graphite-rich schist (likely graphite ore)
Graphite-bearing schist; predominantly graphitic carbon (C) with mica, quartz, and possible feldspar
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (often called Flint)
Microcrystalline Quartz (SiO2)
Chert (Black Flint)
Silicon Dioxide (SiO2)
Fossilized Horn Coral
Order Rugosa (Rugose Coral)
Glauconitic Sandstone
Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2 in Quartz Sandstone
Granite / Feldspar gravel
Granite (felsic intrusive igneous rock)
Red Coral (Precious Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
Black Jasper
Silicon dioxide (SiO2)
Chert (often called Flint or Chalcedony Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert / Flint
Microcrystalline or cryptocrystalline quartz (SiO2)
Amber
Succinite (organic fossilized resin)
Amber
Succinite (approximate formula C10H16O)
Dendritic Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Petrified Wood
Silicified Wood (SiO2)
Anthracite Coal
Carbon (with organic impurities)
Amber
Fossilized Tree Resin
Amber
Succiniferous fossil resin (C10H16O)
Freshwater Pearl
Calcium Carbonate (CaCO3) in the form of Aragonite and Calcite
Amber
Succiniferous fossil resin (C10H16O)
Amber (Copal)
Fossilized Tree Resin (C10H16O)
Moss Agate
Silicon dioxide (SiO2) with mineral inclusions
Banded Chert
Sedimentary Cryptocrystalline Quartz (SiO2)
Shale
Clastic sedimentary rock (primarily clay and silt minerals)
Chert (Jasper/Flint variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Amber
Succinates (Organic compound: C10H16O)
Polished green moss agate cabochon
Moss agate: microcrystalline quartz (SiO₂) with included chlorite/actinolite or iron-manganese minerals
Amber
Succinicum (Formula: C10H16O)
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2 with chlorite inclusions)
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxide
Pink Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Amber
Succinite (amorphous organic polymer)