Pearls (likely freshwater cultured pearls)
Pearl: nacre, primarily aragonite (CaCO₃) with conchiolin
gemstone
Category
Organic Material
Browse organic material specimens identified by the Rock Identifier community.
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Jet
Lignite (Precursor organic rock)
gemstone
Red coral chip bracelet
Corallium spp.; skeleton composed primarily of calcium carbonate (aragonite)
gemstone
Likely bituminous coal
Coal, predominantly carbon-rich organic matter; exact rank cannot be confirmed from the image
sedimentary
Fossilized Shell Fragment / Mother of Pearl
Calcium Carbonate (CaCO3) - Aragonite/Calcite biomineral
fossil
Amber
Succinate (Fossilized Tree Resin)
mineraloid
Potassium-Rich Silicate Clay (inferred from biological context)
Phyllosilicate group (likely Illite or Smectite within surrounding soil substrate)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Poppy Jasper
Microcrystalline Quartz (SiO2) with mineral inclusions
sedimentary
Chert (Jasper variation)
Chert (Cryptocrystalline microcrystalline Silicon Dioxide, SiO2)
sedimentary
Fossilized Dinosaur Bone
Permineralized Dinosaur Bone
fossil
Fossil Shell
Brachiopod or Mollusk fossil
fossil
Fossiliferous Limestone
Calcium Carbonate (CaCO3)
sedimentary
Amber
Succinite (C10H16O)
mineraloid
Fossil Shark Tooth
Carcharodon sp. (likely Otodus or similar Lamniformes order)
sedimentary
Red coral beads (possibly dyed or imitation coral)
Corallium spp. skeleton, composed mainly of calcium carbonate (calcite); exact material cannot be confirmed from the image
gemstone
Gravel / Limestone Fragment
Calcium Carbonate (CaCO3) / Fine-grained Sedimentary Rock
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock (CaCO3)
sedimentary
Red/orange coral beads (likely dyed or treated coral)
Corallium spp.; calcium carbonate, mainly calcite (CaCO₃)
gemstone
Sedimentary Rock (Limestone or Siltstone pebble)
Sedimentary rock fragment
sedimentary
Fossiliferous Sandstone with Plant Remains
Arenite with Carbonaceous impressions (likely Paleozoic/Mesozoic Flora)
sedimentary
Fossilized Bivalve
Phylum Mollusca
fossil
Petrified Wood
Silicified Wood (SiO2)
fossil
Quartz-veined Limestone
Sedimentary limestone with quartz/calcite veinlets
sedimentary
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with organic fossils
sedimentary
Dinosaur Bone Fossil
Permineralized Dinosaur Bone
fossil
Gastropod Fossil
Gastropoda
fossil
Jasper
Silicon dioxide (Microcrystalline quartz, SiO2)
sedimentary
Likely bituminous coal
Coal, predominantly maceral-rich carbonaceous material (composition varies)
sedimentary
Calcite
Calcium Carbonate (CaCO3)
mineral
Coarse Sand or Fine Gravel
Detrital Sedimentary Fragments (mostly SiO2)
sedimentary
Pink coral and green-stone jewelry
Likely pink coral (calcium carbonate, CaCO₃) set with an unidentified green stone; the image is too indistinct to identify the green material reliably.
gemstone
Fossil bivalve shell
Ribbed pectinid or related bivalve; originally calcite/aragonite (CaCO₃), likely partially mineralized
fossil
Chert (Flint)
Silicon dioxide (SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Fossilized coral or silicified organic limestone
Likely fossil coral (Scleractinia/Tabulata) replaced or cemented by calcite and silica; exact identification requires close examination
fossil
Chert (Jasper/Chalcedony mix)
Microcrystalline Quartz (SiO2)
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chert Nodules in Limestone
Cryptocrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)
sedimentary
Limestone
Calcium carbonate (CaCO3)
sedimentary
Shark Tooth Fossil
Selachii fossil
fossil
Shark Tooth Fossil
Chondrichthyes fossil
fossil