Mother of Pearl (Nacre)
Aragonite (CaCO3) with Organic Matrix
mineral
Category
Organic (Biological Organism)
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Amber
Succinite (fossilized organic resin)
mineral
Amber
Succinite (Organic Mineraloid) - C10H16O
mineral
Coal (likely Bituminous or Lignite)
Organic Sedimentary Rock (Carbonaceous)
sedimentary
Amber
Succinite (Fossilized Tree Resin)
fossil
Shale
Fissile mudstone (primarily clay minerals and silt-sized quartz)
sedimentary
Amber (with potentially inclusions)
Succinite (Fossilized Tree Resin)
Mineraloid
Druzy Quartz on Vesicular Basalt
Silicon Dioxide (SiO2) in an extrusive Mafic igneous host rock
igneous
Glauconitic Sandstone
Glauconitic Sandstone (Greensand)
sedimentary
Limestone
Sedimentary rock composed primarily of Calcium Carbonate (CaCO3)
sedimentary
Fossiliferous Limestone (Hash)
Bioclastic Grainstone / Calcarenite
fossil
Fossilized Coral (Petoskey Stone precursor)
Hexagonaria percarinata (Fossilized Rugose Coral)
fossil
Mother of Pearl (Nacre) / Shell Fragment
Biogenic Calcium Carbonate (Aragonite and Conchiolin)
fossil
Coarse Sand or Fine Gravel
Detrital Sedimentary Fragments (mostly SiO2)
sedimentary
Limestone Pebble with Crinoid Fossil
Calcium Carbonate (CaCO3) - Fossiliferous Limestone
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Pink Coral
Corallium rubrum (or related species, composed of calcium carbonate)
gemstone
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Ferruginous Sandstone with Concretion
Sandstone (SiO2 dominated with Fe2O3 cement)
sedimentary
Stromatolite
Biogenic Sedimentary Rock (composed predominantly of CaCO3)
sedimentary
Travertine
Terrestrial Sedimentary Limestone (CaCO3)
sedimentary
Amber and Citrine Quartz
Succinite (Amber) and Silicon Dioxide (SiO2 / Citrine)
mineral
Amber
Succinite (fossilized resin, C10H16O)
mineral
Fossilized Shark Tooth or Bone Fragment
Vertebrate Fossil (likely Carcharodon or similar genus)
fossil
Limestone
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Sandstone (Glauconitic)
Glauconitic Quartz Sandstone (SiO2 + (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
Baltic Amber
Succinite (Fossilized Resin)
fossil
Moss Agate
Chalcedony (SiO2) with dendritic inclusions of Manganese or Iron oxide
mineral
Precious Coral
Corallium rubrum (Calcium carbonate with trace carotene)
Organic gemstone / Sedimentary mineraloid
Amber (Raw)
Succinite (Fossilized Resin)
mineraloid
Red coral cabochon (likely dyed or reconstructed coral)
Corallium rubrum or other calcareous coral; chiefly aragonite (CaCO₃)
gemstone
Natural freshwater pearls
Pearl (nacreous calcium carbonate; chiefly aragonite, CaCO₃)
gemstone
Travertine (Tufa)
Chemical Limestone (CaCO3)
sedimentary
Glauconite (Greensand)
(K, Na)(Fe3⁰, Al, Mg)₂(Si, Al)₄O₁₀(OH)₂
sedimentary
Banded Agate (specifically Moss Agate or Plume Agate variety)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
mineral
Amber
Succinite (C10H16O)
mineraloid
Sandstone Concretion with Fossil Wood
Ferruginous Sandstone Concretion (SiO2 with Fe2O3 cement)
sedimentary
Sandstone (with potential trace fossils)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Polished petrified wood
Silicified fossil wood, chiefly microcrystalline quartz (SiO₂)
fossil
Fossiliferous Sandstone with Plant Remains
Arenite with Carbonaceous impressions (likely Paleozoic/Mesozoic Flora)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Red Coral (Sponge Coral / Apple Coral)
Corallium rubrum (calcium carbonate / organic gem)
gemstone