Chert (varieties include Flint and Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Category
Browse organic gemstone (not a rock or mineral) specimens identified by the Rock Identifier community.
Chert (varieties include Flint and Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Green Chert)
Microcrystalline silica (SiO2)
Boulder Opal
Hydrated Silica (SiO2·nH2O)
Chert (specifically Tan/Yellow Chert)
Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)
Septarian Nodule (Polished)
Septarian concretion (Calcite, Aragonite, Limestone)
Amber
Succinite (organic mineraloid); Chemical formula: C10H16O
Pyrite Geode (Sparkling Druzy)
Iron Sulfide (FeS2) in Sedimentary Nodule
Petrified Wood
Silicified Wood (SiO2)
Chert / Jasper
Microcrystalline Quartz (SiO2)
Sandstone
Arenite (primarily composed of SiO2)
Quartz (Smoky/Granular variety)
Silicon Dioxide (SiO2)
Green Aventurine
Quartz with Fuchsite inclusions (SiO2)
Bloodstone (Heliotrope)
Cryptocrystalline Quartz (SiO2 with iron oxide inclusions)
Banded Sedimentary Rock (Siltstone/Mudstone with concretion)
Siltstone with Ferruginous Banding
Pink Mimbres Agate / Plume Agate
Silicon dioxide (SiO2) with mineral inclusions
Quartz
Silicon Dioxide (SiO2)
Mosasaur Tooth Fossil
Mosasaurus sp.
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (primarily SiO₂ / Silicon Dioxide)
Limestone with Calcite Veining
Sedimentary Carbonate Rock (CaCO3)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Chert (with Drusy Quartz Pocket)
Silicon Dioxide (SiO2)
Ironstone Concretion
Siderite / Hematite-bearing Sedimentary Rock
Jasper
Jasper (Silicon Dioxide, SiO2)
Chert (Sedimentary Rock)
Silicon Dioxide (SiO2)
Rhodochrosite Pebble
MnCO3 (Manganese Carbonate)
Chert (Flint Nodular)
Chert (Silicon dioxide, SiO2)
Red Jasper
Silicon Dioxide (SiO2)
Petrified Wood
Silicified wood (primarily quartz, SiO2)
Quartz
Silicon Dioxide (SiO2)
Amber
Succinite (fossilized resin, C10H16O)
Chalcedony Nodule / Agate
Silicon Dioxide (SiO2)
Clear Quartz
Silicon dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Quartz
Silicon Dioxide (SiO2)
Sandstone Concretion
Clastic sedimentary rock (primarily Quartz SiO2)
Fossilized Bivalve Shell (Fossilized Clam)
Bivalvia (class) / CaCO3 (Calcium Carbonate)
Chalcedony
Silicon Dioxide (SiO2)
Petrified Wood
Silicified wood (Quartz replacement of organic wood structure)
Chert / Flint
Cryptocrystalline Quartz (Silicon Dioxide, SiO2)
Chert (Cherty Flint/Jasper variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Quartz Vein in Sedimentary Matrix
Silicon Dioxide (SiO2) with host rock