Limestone (Concretionary or Tufa)
Calcium Carbonate (CaCO3)
Category
Browse organic gemstone (sedimentary associations) specimens identified by the Rock Identifier community.
Limestone (Concretionary or Tufa)
Calcium Carbonate (CaCO3)
Naga Silver-Inlaid Ebony and Bone/Horn Beads
Diospyros (Ebony) or Keratin (Horn) with Silver/White-Metal Inlay
Amber
Succinite (specifically for Baltic amber); Fossilized Tree Resin (C10H16O)
Amber
Succinite (C10H16O)
Amber
Succinite (specific to Baltic amber), fossilized tree resin
Pyrite
Iron Sulfide (FeS2)
Greenstone / Chert
Cryptocrystalline Quartz (SiO2) or Altered Basalt
Amber
Succinite (fossilized resin); C10H16O
Chert (Chert / Flint)
Silicon dioxide (SiO2) - Microcrystalline quartz
Chert (Flint variety)
Silicon Dioxide (SiO2)
Chert (variations include Flint/Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Limestone (Porous/Travertine variant)
Sedimentary Calcium Carbonate (CaCO3)
Chert (specifically Blue Chert or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Amber
Succinite (specifically for Baltic amber); Approximate formula: C10H16O
Chert
Microcrystalline Quartz (SiO2)
Baroque Pearl
Calcium Carbonate (Aragonite or Calcite) and Conchiolin
Tufa (Limestone)
Calcareous Tufa (CaCO3)
Gastropod Steinkern (Fossil Snail Internal Mold)
Class Gastropoda (Internal Mold)
Chert (Smooth River Pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Amber
Amber (C10H16O)
Fossil Shark Tooth (Otodus obliquus)
Otodus obliquus; hydroxyapatite (mineralized form Ca5(PO4)3(OH))
Jasper
Silicon dioxide (SiO2) with iron inclusions
Epidote in Quartz
Quartz with Epidote inclusions (SiO2 with Ca2(Al,Fe)3(SiO4)3(OH) inclusions)
Chert (specifically Flint or Gray Chert)
Silicon Dioxide (SiO2)
Chert (and/or River Pebble)
Microcrystalline silica (SiO2)
Chert (Flint)
Cryptocrystalline Quartz (SiO2)
Chert Pebble
Microcrystalline Quartz (SiO2)
Fossilized Echinoid (Sea Urchin)
Echinoidea (Class) - Often found as Micraster or Clypeaster specimens
Chert (River Pebble)
Chert (Silicon Dioxide, SiO2)
Chert (River Pebble)
Microcrystalline silica (SiO2)
Fossiliferous Limestone
Biogenic Limestone (CaCO3)
Fossiliferous Limestone (Crinoid stem)
CaCO3 (Calcium Carbonate) with Fossil Inclusions
Chert (Limestone-based)
Silicon dioxide (SiO2)
Chert (Nodular or Fossiliferous)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Arrowhead Fragment)
Microcrystalline Quartz (SiO2)
Chert (with Quartz vein/coating)
Microcrystalline Quartz (SiO2)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Chert (variously known as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Nodule)
Chert (Silicon Dioxide, SiO2)