Shale or Mudstone (Based on appearance)
Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)
Category
Browse organic gemstone (sedimentary classification) specimens identified by the Rock Identifier community.
Shale or Mudstone (Based on appearance)
Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)
Carnelian
Carnelian (SiO2)
Amber
Succinite (fossilized tree resin)
Botryoidal Chalcedony
Silicon Dioxide (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Amber
Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O
Jasper (Petrified Wood variant)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Stromatolite (Jasper-replaced)
Fossilized Stromatolite (Cyanobacteria / Cryptozon / Silica SiO2)
Grey and White Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Ironstone Concretion / Limonite Node
Ferruginous Sedimentary Rock (composed primarily of Limonite FeO(OH)·nH2O and Goethite)
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
Petrified Wood
Silicified Wood (SiO2)
Variscite in Matrix
Variscite (AlPO4 · 2H2O)
Jasper
Silicon dioxide (SiO2)
Carnelian
Carnelian (subset of Chalcedony); SiO2 with Iron Oxide impurities
Jasper (likely Brown or Brecciated)
Jasper (Silicon Dioxide, SiO2)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Petrified Wood
Silicified Wood (SiO2)
Chert (specifically Tan/Brown Chert)
Chert (SiO2)
Septarian Nodule
Septarian Concretion (CaCO3 with Siderite/Calcite/Aragonite)
Jasper
Jasper (Silicon Dioxide, SiO2)
Glauconitic Sandstone (or Greensand)
Glauconitic Siliciclastic Rock (Containing (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
Banded Chert (Jasper)
Silicon Dioxide (SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Chert (specifically Jasper or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Beaded Jewelry (Assorted Gemstones)
Various minerals, including but not limited to Quartz (SiO2), Garnet (X3Y2(SiO4)3), Jade (Na(Al,Fe)Si2O6), Amethyst (SiO2),等の多様な組み合わせ
Shale
Shale
Septarian Nodule
Septarian Concretion
Chert Pebble with Quartz Veins
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Red Jasper
Jasper (Silicate mineral - SiO2)
Red Jasper
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Blue Chalcedony
Silicon Dioxide (SiO2)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminium phosphate)
Opal
Hydrated Silica (SiO2·nH2O)
Turquoise (likely Sleeping Beauty variety or treated Howlite imitation)
Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
Quartz (Pale Rose or Milky Variety)
Silicon Dioxide (SiO2)
Healer's Gold (Pyrite and Magnetite in Schist)
Magnetite (Fe3O4) and Pyrite (FeS2) in Mica Schist
Kyanite
Kyanite (Al2SiO5)