Petrified Wood (Calamites Fossil)
Calamites sp. (Silicified/Permineralized Plant Fossil)
sedimentary
Category
Mineral (Organic Gemstone)
Browse mineral (organic gemstone) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
sedimentary
Amber
Succinite (Fossilized Resin C10H16O)
Organic Mineraloid
Glauconitic Sandstone
Glauconitic Sandstone (contains (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
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
Asphalt / Bituminous Aggregate
Bituminous mixture (Hydrocarbon-based sediment)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)
sedimentary
Peridot
Olivine (Mg, Fe)2SiO4
mineral
Citrine Quartz
Silicon Dioxide (SiO2)
mineral
Citrine
Crystalline Quartz (SiO2) with iron impurities
mineral
Malachite with Chrysocolla
Copper carbonate hydroxide (Cu2CO3(OH)2) and Hydrated copper silicate (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Spiny Oyster Shell
Spondylus (Calcium Carbonate, CaCO3)
mineral
Chert (often called Flint when dark)
Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)
sedimentary
Green Moss Agate
Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite
sedimentary
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Amber
Succinite (fossilized resin)
mineral
Potassium-Rich Silicate Clay (inferred from biological context)
Phyllosilicate group (likely Illite or Smectite within surrounding soil substrate)
mineral
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Moss Agate
Silicon Dioxide (SiO2) with inclusions
mineral
Septarian Nodule (Dragon Stone)
Septarian concretion (composition: CaCO3 - Calcite, Aragonite, and Siderite/Limestone)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Coral Fossil (Scleractinia)
Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood / Chalcedony (SiO2)
mineral
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Commonly known as Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Limestone with Calcite Veins
Calcium Carbonate (CaCO3)
sedimentary
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Green Calcite
Calcium Carbonate (CaCO3)
mineral
Amber
Succinite (Carbon-based organic compound; approximate formula C10H16O)
Mineraloid
Chert (Flint variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Olivine (Peridotite)
Magnesium iron silicate (Mg, Fe)2SiO4
igneous
Quartzite with inclusions
Quartzite
metamorphic
Chert (with Quartz Vein)
Chert (Siliceous sedimentary rock, predominantly Microcrystalline Quartz SiO2)
sedimentary
Glauconitic Sandstone (Greensand pebble)
Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
sedimentary
Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Fossilized Coral
Scleractinia (fossil order), primarily Calcium Carbonate (CaCO3)
sedimentary