Chert (Nodular)
Chert (SiO2 - Microcrystalline Quartz)
sedimentary
Category
Organic (Sedimentary Context)
Browse organic (sedimentary context) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
sedimentary
Chert Pebble with Quartz Veins
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Chert (specifically Tan/Brown Chert)
Chert (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
mineral
Shale or Argillite
Shale (sedimentary) / Argillite (metamorphic)
Sedimentary or Metamorphic (low-grade)
Chert (Chert Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Iron-stained River Cobble)
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Amber (Cherry or Red variety)
Succinite (with various trace amounts of organic compounds)
Organic Gemstone (not a rock)
Banded Agate (specifically Moss Agate or Plume Agate variety)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
mineral
Petrified Wood
Silicified Wood (primarily SiO2)
metamorphic
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Sedimentary or Metamorphic (low grade)
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of organic matter)
sedimentary
Gastropod Fossil (Internal Mold)
Phylum Mollusca, Class Gastropoda (Steinkern)
sedimentary
Chert (specifically Jasper or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Baltic Amber
Succinite (Polmerized conifer resin)
mineraloid
Petrified Wood
Silicified Wood (primarily Quartz / Chalcedony: SiO2)
metamorphic
Chert (specifically a stream-worn Chert Nodule)
Sedimentary Cryptocrystalline Quartz (SiO2)
sedimentary
Travertine (Tufa)
Calcium Carbonate (CaCO3)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Petoskey Stone
Hexagonaria percarinata (Fossilized Coral)
sedimentary
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Amber
Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O
Organic mineraloid
Septarian Nodule (Dragon Stone)
Septarian Nodule (Calcium Carbonate/Aragonite/Calcite Concretion)
sedimentary
Amber
Succinite (fossilized tree resin)
mineraloid / sedimentary organic material
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Graphite
Graphite (Carbon, C)
Mineral
Pink Opal / Peruvian Opal
Hydrated amorphous silicon dioxide (SiO2·nH2O)
Mineral
Quartzite and Chert
Silicon Dioxide (SiO2)
metamorphic and sedimentary
Fossilized Gastropod (Snail)
Class Gastropoda (internal mold or 'steinkern')
sedimentary
Petrified Wood
Silicified wood (primarily Silicon Dioxide - SiO2)
mineral (silicate-replaced organic material)
Septarian Nodule (Septarian Dragon Stone)
Septarian Concretion (Composition: Calcite, Aragonite, and Limestone/Clay)
sedimentary
Mookaite Jasper
Siliceous (chert) sedimentary rock, a form of Jasper
Sedimentary
Chert (Arrowhead or Projectile Point)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Precious Coral
Corallium rubrum (Calcium carbonate with trace carotene)
Organic gemstone / Sedimentary mineraloid
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
mineral