Anthracite Coal
Anthracite (Highly Metamorphosed Coal)
sedimentary
Category
Mineral And Organic Gemstone
Browse mineral and organic gemstone specimens identified by the Rock Identifier community.
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Quartz Pebble (with Iron Inclusions)
Silicon Dioxide (SiO2)
mineral
Chert (Jasper/Chalcedony)
Microcrystalline Silica (SiO2)
sedimentary
Picasso Jasper (or Picasso Marble)
Metamorphosed Limestone (Calcium Carbonate, CaCO3, with impurities)
metamorphic
Fossilized Vertebra
Chordata fossil (Vertebra)
fossil
Chert / Flint
Cryptocrystalline Quartz (SiO2)
sedimentary
Green Slate or Metamorphic Rock with Moss/Lichen
Metamorphic rock / Phyllite or Slate variant
metamorphic
Fossiliferous Limestone / Petrifaction
Sedimentary rock with fossil inclusions / Calcium Carbonate (CaCO3)
fossil
Ironstone Concretion (Moqui Marble / Boji Stone)
Sedimentary Iron Oxide Concretion (Fe2O3 / FeO(OH))
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Chert (often called Flint in archaeological contexts)
Silicon Dioxide (SiO2)
sedimentary
Chert (Banded Variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Tumbled amber
Amber (fossilized plant resin), chiefly polymerized diterpenoid resin
gemstone
Fancy Jasper
Silicon dioxide (SiO2)
sedimentary
Chert (including Flint and Jasper variants)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Amber
Succinite (a common variety of fossilized resin)
mineral
Chert (with Limestone matrix)
Chert (Silica: SiO2)
sedimentary
Fossil Shark Tooth
Otodus sp. or Carcharocles sp. (likely fossilized Chondrichthyes)
fossil
Sandstone
Sandstone (SiO2-dominated clastic rock)
sedimentary
Fossilized Bone
Permineralized Vertebrate Fossil
sedimentary
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Chert (Flint variety)
Chert (Cryptocrystalline Quartz, SiO2)
sedimentary
Chert (specifically Red Chert or Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Chalcedony/Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Cultured freshwater pearls
Pearl; primarily aragonite (CaCO₃) in nacre with an organic conchiolin matrix
gemstone
Polished amber inclusion specimen
Amber (fossilized plant resin), commonly succinite; organic mineraloid
gemstone
Amber (likely rough amber or copal)
Fossilized tree resin; chiefly an organic polymer with terpenoid remnants
gemstone
Likely anthracite coal fragments
Anthracite; predominantly carbon (C), with minor mineral ash
sedimentary
Amber
Succinite (fossilized tree resin)
mineraloid
Fossilized Shell
Invertebrate fossil (Bivalvia or Brachiopoda)
fossil
Fossil Shell
Brachiopod or Mollusk fossil
fossil
Grass (Organic Matter/Soil)
Poaceae (family of monocotyledonous flowering plants)
Organic Materia (Not a rock or mineral)
Fossilized Shark Tooth
Carcharocles or Otodus sp. (Micro-fossilized)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Amber
Succinite (a fossilized organic resin containing succinic acid)
mineraloid
Chert (and/or Chalcedony)
Microcrystalline Silica (SiO2)
sedimentary
Chert (variations include Flint/Novaculite)
Chert (formula: SiO2)
sedimentary
Chert (often called Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Jasper (specifically Yellow Jasper and Red Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Moss Agate
Silicon Dioxide with inclusions (SiO2 + Mn/Fe/Chlorite)
mineral
Jasper
Silicon Dioxide (SiO2) with impurities
sedimentary
Green Moss Agate
Agate (Silicon Dioxide, SiO2) with inclusions of hornblende or chlorite
mineral