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