Chalcedony (Botryoidal/Tumbled Agate)
Silicon Dioxide (SiO2)
Category
Browse organic gemstone (sedimentary classification) specimens identified by the Rock Identifier community.
Chalcedony (Botryoidal/Tumbled Agate)
Silicon Dioxide (SiO2)
Amber
Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O
Petrified Wood
Silicified wood (Quartz, SiO2)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Orange Calcite
Calcium Carbonate (CaCO3)
Chert (Grey-Green Var.)
Silicon Dioxide (SiO2)
Pink Garnet (likely Almandine or Rhodolite)
Garnet Group (Fe3Al2(SiO4)3 to Mg3Al2(SiO4)3)
Asphalt (Bituminous pavement)
Bituminous concrete / Asphalt
Petrified Wood
Silicified Wood (SiO2)
Rhodochrosite
Manganese carbonate (MnCO3)
Shale or Mudstone (Based on appearance)
Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)
Dalmatian Jasper
Peralkaline rhyolite with arfvedsonite inclusions
Carnelian (Chalcedony)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Jasper (Petrified Wood variant)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Grey and White Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Stromatolite (Jasper-replaced)
Fossilized Stromatolite (Cyanobacteria / Cryptozon / Silica SiO2)
Opal
Hydrated Silica (SiO2·nH2O)
Botryoidal Chalcedony
Silicon Dioxide (SiO2)
Quartz
Silicon dioxide (SiO2)
Amber
Fossilized tree resin
Chert (Smooth River Pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Jasper with Quartz Vein
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Jasper-bearing)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Fossil Coral (Favosites Honeycomb)
Favosites (Genus), Phylum Cnidaria, Class Anthozoa
Petrified Wood
Silicified Wood (SiO2)
Jasper (Iron-stained Chert)
Silicon Dioxide (SiO2) with impurities of Hematite or Goethite
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
Turquoise (Rough)
Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
Red Jasper
Silicon Dioxide (SiO2)
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Zoisite with Hornblende
Zoisite (Ca2Al3(SiO4)3(OH)) with Amphibole inclusions
Hematite Nodular Concretion
Iron(III) oxide (Fe2O3)
Dalmation Stone
Peralkaline Rock (mixed silicate minerals)
Red Jasper (Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
Orange Calcite (Mexican Onyx)
Calcium Carbonate (CaCO3)
Opal
Hydrated amorphous silica (SiO2·nH2O)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Agate (or Chalcedony)
Silicon Dioxide (SiO2)
Turquoise in Matrix
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)