Fossiliferous Limestone with Rugose Coral
Calcite (CaCO3) matrix containing Rugosa (order of extinct solitary and colonial corals)
sedimentary
Category
Organic Gemstone (Sedimentary Classification)
Browse organic gemstone (sedimentary classification) specimens identified by the Rock Identifier community.
Learn about Organic Gemstone (Sedimentary Classification) in the encyclopedia
View all →
Fluorite
Fluorite (CaF2)
mineral
Shungite
Non-crystalline carbonoid (Shungite)
metamorphic
Amber
Succinite (Fossilized Tree Resin)
gemstone
Moss Agate
Chalcedony (Silicon Dioxide - SiO2) with inclusions
Mineral
Possible basaltic rock or meteorite candidate
Likely vesicular basalt; meteorite identification cannot be confirmed visually
igneous
Pyrite
Iron Sulfide (FeS2)
mineral
Mother of Pearl (Nacre) / Shell Fragment
Biogenic Calcium Carbonate (Aragonite and Conchiolin)
fossil
Limestone Pebble with Crinoid Fossil
Calcium Carbonate (CaCO3) - Fossiliferous Limestone
sedimentary
Chert / Flint
Microcrystalline Quartz (SiO2)
sedimentary
Angel Skin Coral
Corallium rubrum / Corallium spp. (Calcium Carbonate, CaCO3)
gemstone
Amber
Succinite (C10H16O)
mineral
Sedimentary Rock with Crafts (Pet Rock)
Sedimentary rock decorated with synthetic materials
sedimentary
Anthracite Coal
Carbon (with organic impurities)
sedimentary
Fossilized Coral (Petrified Coral)
Lithostrotionella (example genus) / Scleractinia
fossil
Chert (Green and Black Jasper variant)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Jasper variation)
Chert (SiO2)
sedimentary
Fossiliferous Limestone
Bioclastic Limestone (CaCO3)
sedimentary
Fossiliferous Sedimentary Rock
Sedimentary Rock with Invertebrate Fossil Imprint
fossil
Amber
Succinite
Mineraloid
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
mineral
Pearl
Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3
mineral
Moss Agate / Chalcedony
Silicon Dioxide (SiO2)
mineral
Pearl
Aragonite / Calcium Carbonate (CaCO3)
mineral
Amber
Succinite (C10H16O)
gemstone
Fossil Crab
Decapoda (likely Avitelmessus or Raninidae family)
sedimentary
Limestone and Quartz Gravel with Petrified Wood
Sedimentary gravel aggregate and fossilized wood
sedimentary
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Jasper
Silicon dioxide (SiO2)
sedimentary
Chert (Flint nodule)
Chert (SiO2)
sedimentary
Pearl (with Peridot)
Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4
mineral
Siderite Concretion in Shale
Iron carbonate (FeCO3) in Mudstone/Shale matrix
sedimentary
Moss Agate
SiO2 (Cryptocrystalline Quartz)
gemstone
Limestone Pebble
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Fossilized Tooth Fragment
Vertebrate Fossil (Mammalia indet.)
fossil
Amber
Succinite (fossilized tree resin)
fossil
Black Pearl (Tahitian-style Cultured Pearl)
Calcium Carbonate (Aragonite) with Conchiolin (CaCO3)
mineral
Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Black Freshwater Pearls
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Moss Agate
Cryptocrystalline Quartz (SiO2 with Manganese or Iron Oxide inclusions)
mineral