Pink Opal
Hydrated silicon dioxide (SiO2·nH2O) with inclusions
mineral
Category
Organic Structure (Not A Rock)
Browse organic structure (not a rock) specimens identified by the Rock Identifier community.
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Petrified Wood
Silicified Wood (SiO2)
fossil
Sand Tiger Shark Tooth Fossil
Carcharias taurus (fossilized tooth)
fossil
Chert (specifically Chalcedony or Flint variation)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Gravel specimen)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Red Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Copper-bearing Quartz Vein in Host Rock
Quartz with Malachite/Chrysocolla staining
igneous/metamorphic with mineral
Ulexite
NaCaB5O6(OH)6·5H2O
mineral
Basalt
Aphanitic Mafic Igneous Rock
igneous
Serpentine
Antigorite, Lizardite, or Chrysotile (Mg, Fe)3Si2O5(OH)4
metamorphic
Kambaba Jasper (Crocodile Jasper)
Rhyolite containing Fossilized Cyanobacteria (Stromatolite)
sedimentary
Moss Agate
Silicon Dioxide with inclusions (SiO2 + impurities)
mineral
Basalt
Extrusive Igneous Rock
igneous
Quartz with Host Rock
Silicon Dioxide (SiO2)
mineral
Orbicular Jasper (Ocean Jasper)
Silicon Dioxide (SiO2) with various inclusions
mineral
Chert (Nodule)
Silicon Dioxide (SiO2)
sedimentary
Chert (Quartz Variety)
Microcrystalline Silica (SiO2)
sedimentary
Chert Pebble (Flint)
Microcrystalline/Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (variations include Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Petrified Wood / Fossilized Wood
Silicified Wood (Silicon Dioxide - SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2 permineralization)
fossil
Granite
Felsic intrusive igneous rock
igneous
Basalt
Basalt (Aphanitic-fine grained mafic igneous rock)
igneous
Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Picture Jasper
Silicon Dioxide (SiO2) - Opaque Chert/Quartzite variety
sedimentary
Quartz Geode
Crystalline Quartz (SiO2) within a sedimentary/igneous host
mineral
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Chert (Flint Nodular)
Chert (Silicon dioxide, SiO2)
sedimentary
River Pebble (likely Quartzite or Chert)
Sedimentary Clast (Silicon Dioxide dominant)
sedimentary
Petrified Wood
Silicified wood (primarily quartz, SiO2)
fossil
Basalt Pebble
Extrusive Igneous Rock
igneous
Vesicular Basalt (Lava Rock)
Basalt (Vesicular Variety)
igneous
Chert (specifically Chert Nodule/Flint)
Chert (Silicon Dioxide, SiO2)
sedimentary
Mookaite Jasper
Silicon Dioxide with Iron Oxide impurities (SiO2)
mineral
Chert (with Quartz veins)
Chert (Microcrystalline Silicon Dioxide, SiO2)
sedimentary
Petrified Wood
Silicified wood (SiO2)
fossil
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Pink Chert (Brecciated Jasmine/Jasper)
Silicon Dioxide (SiO2)
sedimentary
Quartz Geode
Crystalline Silicon Dioxide (SiO2) in a Geodic Concretion
mineral
Quartz Geode
Silicon Dioxide (SiO2) in a sedimentary or volcanic host
mineral