Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Category
Browse organic gemstone (sedimentary classification) specimens identified by the Rock Identifier community.
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Coquina / Limonite-stained Limestone
Sedimentary Limestone with Iron Oxyhydroxide (FeO(OH)·nH2O)
Chert (Tan/Yellow variety)
Microcrystalline quartz (SiO2)
Turquoise, Pearl, and Coral Necklace
CuAl6(PO4)4(OH)8·4H2O (Turquoise) / CaCO3 (Pearl and Coral)
Shale
Fissile mudstone (primarily clay minerals and silt-sized quartz)
Banded Chert
Silicon Dioxide (SiO2)
Amber
Succiniferous fossil resin (C10H16O)
Fossil Shell Fragment (possibly Brachiopod or Bivalve)
Calcium Carbonate (CaCO3) - Phylum Brachiopoda or Mollusca
Chert (Jasper)
Silicon dioxide (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Coquina (Fossiliferous Limestone)
Coquina (Organic Clastic Limestone)
Shale
Fissile mudrock (composed primarily of clay minerals and quartz)
Chert (Jasper)
Silicon Dioxide (SiO2)
Limestone with Bitumen/Chert
Calcite (CaCO3) containing organic hydrocarbons
Travertine
Calcareous tufa (CaCO3)
Amber / Copal
Succinite (fossilized resin)
Chert / Flint
Chert (Microcrystalline Quartz, SiO2)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Chert (Arrowhead Preform or Point)
Chert (Microcrystalline Quartz, SiO2)
Sandstone (with carbonaceous plant fragments)
Arenite (composed primarily of SiO2)
Shell Cameo (Sardonyx Shell)
Cassis madagascariensis (Sardonyx shell)
Amber
Fossilized Tree Resin (Generic formula roughly C10H16O)
Sandstone with Algae Growth
Arenite with Chlorophyta/Lichen
Sandstone Pebble
Arenite (primarily SiO2)
Travertine
Calcareous Tufa / Travertine (CaCO3)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Chert (and Flint)
Silicon Dioxide (SiO2)
Fossilized Shark Tooth
Carcharodon carcharias (fossilized) / Hydroxyapatite permineralized with silica or iron
Chert (specifically Flint Arrowhead)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Sandstone (Weathered Coastal Boulder)
Arenite (composed primarily of SiO2)
Cardstock (Paper)
Cellulose (C6H10O5)n
Ferruginous Sandstone (with possible trace fossils)
Arenite with Iron-Oxide Cement (SiO2 with Fe2O3)
Chert (often called Flint)
Chert (Cryptocrystalline Quartz, SiO2)
Glauconite (Sandstone or Shale)
Glauconite (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2
Fossilized Fish Skeleton in Matrix
Vertebrata (Class: Actinopterygii), typically found in limestone or shale matrices
Chert (Flint variety)
Chert (SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (variations include Flint/Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper)
Microcrystalline Silica (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)