Moss Agate
Silicon Dioxide (SiO2) with inclusions
mineral
Category
Organic Gemstone (Not A Mineral)
Browse organic gemstone (not a mineral) specimens identified by the Rock Identifier community.
Learn about Organic Gemstone (Not A Mineral) in the encyclopedia
View all →
Citrine
Silicon Dioxide (SiO2) with iron impurities
mineral
Chert (Flint)
Microcrystalline or cryptocrystalline quartz (SiO2)
sedimentary
Yellow Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Iron-rich variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Garnet Schist
Almandine Garnet in Schist (X3Al2(SiO4)3)
metamorphic
Chert (often called Flint when dark)
Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)
sedimentary
Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2)
sedimentary
Potassium-Rich Silicate Clay (inferred from biological context)
Phyllosilicate group (likely Illite or Smectite within surrounding soil substrate)
mineral
Amber
Succinite (Carbon-based organic compound; approximate formula C10H16O)
Mineraloid
Petrified Wood
Silicified Wood / Chalcedony (SiO2)
mineral
Limestone with Calcite Veins
Calcium Carbonate (CaCO3)
sedimentary
Septarian Nodule (Dragon Stone)
Septarian concretion (composition: CaCO3 - Calcite, Aragonite, and Siderite/Limestone)
sedimentary
Shungite
Shungite (carbon-rich Precambrian rock)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Shungite
Shungite (carbon-rich Precambrian mineraloid)
mineral
Chert (specifically Green Chert/Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Septarian Nodule
Septarian Concretion (CaCO3 + Hydrated SiO2)
sedimentary
Coral Fossil (Scleractinia)
Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
metamorphic
Onyx (Black) and Mother of Pearl Inlay
Silicon Dioxide (SiO2) for Onyx; Aragonite (CaCO3) for Mother of Pearl
mineral
Prehnite
Prehnite (Ca2Al2Si3O10(OH)2)
mineral
Petrified Wood
Silicified Wood (SiO2)
mineral
Epidote
Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
mineral
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (often called Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (with potential fossil inclusion)
Microcrystalline Quartz (SiO2)
sedimentary
Sand Tiger Shark Tooth (Fossil)
Carcharias taurus (fossilized dentin/enameloid)
fossil
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Fossilized Coral
Scleractinia (fossil order), primarily Calcium Carbonate (CaCO3)
sedimentary
Ironstone Concretion
Siderite or Goethite Concretion
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Amber
Succinite (fossilized resin)
mineral
Fossiliferous Limestone
Limestone (CaCO3 - Calcium Carbonate)
sedimentary
Amber
Succinite (Resinite), C10-H16-O
mineral