Banded Chert
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Category
Browse organic gemstone (sedimentary associations) specimens identified by the Rock Identifier community.
Banded Chert
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Jasper/Brown Chert)
Silicon Dioxide (SiO2)
Chert / Jasper
Microcrystalline Quartz (SiO2)
Red Jasper
Jasper (a cryptocrystalline variety of Quartz, SiO₂)
Larimar and Fossil Coral
Pectolite (NaCa2Si3O8(OH)) and Hexagonaria/Petoskey Stone
Yellow Quartz (Citrine or Yellow Chalcedony)
Silicon Dioxide (SiO2)
Sphalerite
Zinc Sulfide (Zn,Fe)S
Pink Opal
Hydrated silicon dioxide (SiO2·nH2O) with inclusions
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide
Red Dyed Howlite
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
Amber
Succinite (Carbon-based organic compound; approximate formula C10H16O)
Petrified Wood
Silicified Wood (SiO2)
Yellow Jasper
Silicon Dioxide (SiO2)
Peacock Ore
Bornite (Cu5FeS4) or Chalcopyrite (CuFeS2) with iridescent tarnish
Carnelian
Carnelian (variety of Chalcedony, SiO2)
Petrified Wood
Silicified Wood (SiO2 - Quartz/Chalcedony replacement)
Anthracite Coal
Anthracite
Fire Opal
Hydrated Silica (SiO2·nH2O)
Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
Amethyst Geode
Amethyst (Silicon Dioxide), Formula: SiO2
Granite Gneiss with Garnet
Garnetiferous Gneiss
Banded Chert (Jasper)
Silicon Dioxide (SiO2)
Banded Iron Formation (BIF)
Banded Iron Formation (composed primarily of Hematite [Fe2O3], Magnetite [Fe3O4], and Chert [SiO2])
Chert (Jasper/Agate variety)
Microcrystalline quartz (SiO2)
Chert (Nodular Chert)
Microcrystalline Silica (SiO2)
Amber
Succinite (specifically for Baltic amber); C10H16O (Variable organic compound)
Red Amber (Burmite/Cherry Amber)
Succinite / Retinite (Organic Fossilized Resin, C10H16O)
Chalcedony (Agate/Quartz pebble)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Quartz Crystal (specifically a small Clear Quartz point)
Silicon Dioxide (SiO2)
Quartz
Quartz (Silicon Dioxide - SiO2)
Kyanite (in Schist Matrix)
Kyanite (Al2SiO5)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with dendritic inclusions
Aquamarine
Beryl (Be3Al2Si6O18)
Ruby in Zoisite
Ruby (α-Al2O3) embedded in Zoisite (Ca2Al3(SiO4)3(OH)) with some Hornblende
Diamond in Gold Setting
Diamond (C - pure carbon)
Carnelian
Silicon Dioxide (SiO2) - variety of Chalcedony
Peridot
Olivine (Mg, Fe)2SiO4
Quartz
Quartz (SiO2, Silicon Dioxide)
Carnelian
Carnelian (a variety of Chalcedony, SiO2)
Black Onyx
Cryptocrystalline Quartz (SiO2 with organic/iron impurities)
Blue Agate (Tumbled and Dyed)
Silicon Dioxide (SiO2) with likely organic dyes