Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)
Quartz (SiO₂)
Category
Browse organic gemstone (sedimentary associations) specimens identified by the Rock Identifier community.
Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)
Quartz (SiO₂)
Banded Iron Formation (BIF)
Banded Iron Formation (Magnetite/Hematite and Chert)
Chert (or Jasper)
Microcrystalline Quartz (SiO2)
Chert (specifically var. Flint or Jasper-rich Breccia)
Microcrystalline Quartz (SiO2)
Chert (specifically Jasper or Flint variety)
Cryptocrystalline Quartz (SiO2)
Jasper
Chert (Silica: SiO2)
Slate
Slate (foliated metamorphic rock, primarily composed of quartz, illite, chlorite, and micas)
Prasiolite and Quartz Crystal Cluster
Quartz (SiO2); Prasiolite is a variety of Quartz
Petrified Wood
Silicified Wood (SiO2)
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxides
Amber
Succinurite (C10H16O)
Moss Agate
Chalcedony (Silicon Dioxide) with dendritic inclusions (SiO2)
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2
Chert (Flint)
Cryptocrystalline Quartz (SiO2)
Chert (specifically Jasper or Brown Chert node)
Microcrystalline Quartz (SiO2)
Mixed Tumbled Gemstones and River Rocks
Mixed Decorative Stones (predominantly Silicon Dioxide - SiO2 variants)
Quartz (likely Rose Quartz or Milky Quartz based on color)
Quartz (SiO2 - Silicon Dioxide)
Turquoise
Turquoise - CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Almandine Garnet in Schist Matrix
Almandine - Fe3Al2(SiO4)3
Red Jasper (Opaque Chalcedony)
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Coal (most likely Bituminous or Anthracite)
Bituminous Coal (Grade of Coal), Anthracite (Grade of Coal)
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Chrysanthemum Stone
Celestine (SrSO4) or Calcite (CaCO3) in Limestone/Porphyry matrix
Petrified Wood
Silicified Wood (SiO2)
Sandstone
Sandstone (Clastic Sedimentary Rock)
Agate (or Chalcedony)
SiO2 (Silicon Dioxide) - a cryptocrystalline variety of quartz
Petrified Wood
Silicified Wood (SiO2)
Peridot (Olivine)
Magnesium Iron Silicate (Mg, Fe)2SiO4
Quartz
Silicon Dioxide (SiO2)
Opalite
Synthetic Opalised Glass
Chalcedony
Silicon dioxide (SiO2) - Microcrystalline quartz
Amber (Rough)
Amber (Fossilized Tree Resin, succinite)
Amber
Succinate (Fossilized Tree Resin)
Amber with Inclusion
Succiniferous fossil resin (C10H16O)
Magnetite (Iron Ore)
Magnetite (Fe3O4)
Citrine
Silicon dioxide (SiO2) - yellow quartz variety
Brachiopod Fossil (Spiriferid)
Order Spiriferida (Phylum Brachiopoda); mineralized as Calcite (CaCO3) or Chert (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Yellow Chalcedony (Agate/Jasper mix)
Silicon Dioxide (SiO2)
Chert (Jasper variety)
Cryptocrystalline quartz (SiO2)
Banded Chert
Silicon Dioxide (SiO2) - Microcrystalline Quartz