Fossilized Rugose Coral (Horn Coral)
Order Rugosa
Category
Browse mineral and organic gemstone specimens identified by the Rock Identifier community.
Fossilized Rugose Coral (Horn Coral)
Order Rugosa
Polished fossil coral
Agatized or silicified coral, commonly fossilized stony coral (Scleractinia); exact genus cannot be determined from the image
Chert (Jasper)
Microcrystalline quartz (SiO2)
Amber (Copal)
Succinate (Fossilized Tree Resin)
Pyrite
Iron Sulfide (FeS2)
Shark Tooth Fossil
Carcharhiniformes or Lamniformes (order level fossil)
Polished amber cabochon pendant
Amber (fossilized plant resin), chiefly polymerized succinite; approximate formula C10H16O
Tumbled amber-like inclusion
Likely amber (fossilized tree resin; complex polymer), but identification is uncertain from the image
Fossilized Shark Tooth
Chondrichthyes (class)
Mother of Pearl (Nacre)
Aragonite (CaCO3) with Organic Matrix
Limestone (or Sandstone)
Calcium Carbonate (CaCO3) / Silica (SiO2)
Sandstone (with Moss)
Quartz Arenite / Sandstone
Poppy Jasper
Microcrystalline Quartz (SiO2) with mineral inclusions
Amber
Succinite (specific to Baltic amber), fossilized tree resin
Fossilized Bone Fragment
Vertebrate Fossil
Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Graphite
Graphite (Carbon, C)
Chert (Brown variety / Common Jasper)
Microcrystalline Quartz (SiO2)
Petrified wood
Silicified fossil wood; commonly quartz (SiO₂) replacing wood tissue
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
Chert (Cherty Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert / Flint
Chert (SiO2)
Fossilized Bone
Permineralized Vertebrate Bone
Chert (and its variety Flint)
Silicon dioxide (SiO2) / Microcrystalline quartz
Chert (variations like Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Travertine
Tufa limestone (CaCO3)
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2)
Amber in Matrix
Succinite (Carbon-based organic polymer)
Amber
Succinite (fossilized resin)
Amber
Succinite (fossilized tree resin)
Tree Agate (also known as Dendritic Agate)
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
Fossil tooth
Mineralized vertebrate tooth; exact animal and species cannot be determined from the image
Fossil Shark Tooth
Chondrichthyes (Class)
Moss Agate
Chalcedony (SiO2) with inclusions of hornblende or chlorite
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
Probable amber fragment
Amber (fossilized plant resin; chiefly amorphous organic resin, commonly dominated by succinite)
Petrified Wood
Silicified Wood (SiO2)
Chert (Flint Pebbles)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Jasper
Microcrystalline Quartz (SiO2)
Flint/chert nodule with a weathered cortex
Microcrystalline quartz (SiO₂), likely flint or dark chert