Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide
Category
Browse organic gemstone (fossilized resin) specimens identified by the Rock Identifier community.
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide
Moss Agate
Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)
Chert (containing small fossils)
Chert (Microcrystalline Quartz, SiO2)
Fossiliferous Limestone with Rugose Coral
Calcium Carbonate (CaCO3) featuring Rugosa (extinct order of solitary and colony corals)
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Banded Agate (specifically Moss Agate or Plume Agate variety)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Chert (Jasper/Flint variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Moss Agate
Silicon Dioxide (SiO2) with Manganese or Iron Oxide inclusions
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
Shale
Mudstone (composed primarily of clay minerals like kaolinite, illite, and smectite, with quartz and calcite)
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxide
Chert (Flint Nodules)
Microcrystalline Quartz (SiO2)
Dinosaur Bone (Gembone)
Agatized Dinosaur Bone (Silicified Paleo-osteoid)
Baroque Pearl (and potentially a small Sapphire/Blue Topaz)
Pearl: Calcium Carbonate (aragonite or calcite) with conchiolin. Sapphire: Aluminum Oxide (Al2O3). Blue Topaz: Al2SiO4(F,OH)2.
Pyrite
Pyrite (Iron Disulfide), FeS2
Green Jasper
Jasper (Silicates, SiO2)
Chert (Gravel)
Silicon Dioxide (SiO2)
Chert (Jasper/Common Opal mix)
Microcrystalline Quartz (SiO2)
Pyrite in Shale
Iron Sulfide (FeS2) in Sedimentary Matrix
Chert (Jasper-bearing)
Microcrystalline silica (SiO2) with iron oxide inclusions
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Chert (Jasper type)
Microcrystalline Quartz (SiO2)
Chert (Yellow/Tan variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Limestone with Chert or Siltstone bands
Sedimentary carbonate rock (CaCO3) often with siliceous impurities
Chert (specifically Yellow/Tan Chert)
Silicon Dioxide (SiO2)
Black Marble
Recrystallized Limestone (CaCO3)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Chert (Arrowhead/Tool variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (and Flint variant)
Microcrystalline Quartz (SiO2)
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
Chert (Yellow Jasper variant)
Silicon Dioxide (SiO2)
Chert (Yellow/Brown variety)
Chert (SiO2)
Chert (often called Flint when dark or worked)
Cryptocrystalline silica (SiO2)
Chert (Yellow variety / Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
Chert (Chert Nodule with Chalky Cortex)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (often called Flint)
Chert (SiO2)
Pyrite
Iron Sulfide (FeS2)
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Ironstone Concretion / Limonite Node
Goethite and Limonite (FeO(OH) nH2O)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)