Limestone (specifically Bituminous or Carbonaceous Limestone)
Calcium Carbonate (CaCO3) with Organic Impurities
Category
Browse organic (often found by beachcombers) specimens identified by the Rock Identifier community.
Limestone (specifically Bituminous or Carbonaceous Limestone)
Calcium Carbonate (CaCO3) with Organic Impurities
Naga Silver-Inlaid Ebony and Bone/Horn Beads
Diospyros (Ebony) or Keratin (Horn) with Silver/White-Metal Inlay
Amber
Succinite (Formula: C10H16O)
Chert (Jasper)
Silicon Dioxide (SiO2)
Amber
Succinite (fossilized tree resin), C10H16O
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
Amber
Succinite (Organic Gemstone)
Fossil Shark Tooth
Carcharodon sp. (likely Otodus or similar Lamniformes order)
Green Chert
Microcrystalline Quartz (SiO2)
Banded Chert
Silicon Dioxide (SiO2)
Chert (Smoky variety)
Microcrystalline Quartz (SiO2)
Fossil Crab
Decapoda (likely Avitelmessus or Raninidae family)
Rough Amber (likely Copal or immature Amber)
Organic gemstone / Succinite (if Baltic)
Druzy Chalcedony/Quartz on Fluorite core
Silicon Dioxide (SiO2) on Calcium Fluoride (CaF2)
Potassium-Rich Silicate Clay (inferred from biological context)
Phyllosilicate group (likely Illite or Smectite within surrounding soil substrate)
Sandstone Concretion with Fossil Wood
Ferruginous Sandstone Concretion (SiO2 with Fe2O3 cement)
Chert (often found as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (and Fossilized Brachiopod shell)
Sedimentary Cryptocrystalline Quartz (SiO2)
Jasper containing fossilized inclusions
Silicon Dioxide (SiO2) with trace impurities and biogenic inclusions
Glauconitic Sandstone (Greensand pebble)
Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
Glauconitic Sandstone (Greensand)
Glauconitic Sandstone (Iron-potassium phyllosilicate mineral: (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Chert (Nodule)
Cryptocrystalline Quartz (SiO2)
Chert (Chalcedony/Flint)
Silicon Dioxide (SiO2)
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
Red Chert
Microcrystalline Quartz (SiO2)
Amber
Succinite (C10H16O)
Green Chert (Jasper)
Silicon Dioxide (SiO2)
Chert (or Chalcedony)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Chalcedony)
Microcrystalline Silica (SiO2)
Micro-crystalline Quartz Pebble (Chert)
Silicon dioxide (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (Basanite variety)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variant)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Chert (Jasper variation)
Silicon Dioxide (SiO2)
Quartzite with inclusions
Quartzite
Amber
Succinite (specifically for Baltic amber); approximate formula C10H16O
Jasper
Silicon dioxide (SiO2)
Geode with Quartz Crystal Cavity
Silicon Dioxide (SiO2) in Calcareous/Siliceous Matrix
Amber / Copal
Organic resin, C10H16O
Turquoise and Red Coral (with Grizzly Bear Claw)
Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Precious Coral (Corallium rubrum)