Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Category
Browse sedimentary (chemically precipitated mineral) specimens identified by the Rock Identifier community.
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Iron inclusions
Limonite (after Pyrite Pseudomorph)
Limonite (Hydrated Iron Oxide Mixture, FeO(OH)·nH2O)
Grey River Stone (Quartz-rich Quartzite/Siltstone)
Quartzite / Meta-siltstone (primarily SiO2)
Agate
Silicon Dioxide (SiO2) - Cryptocrystalline Chalcedony
Diabase (Dolerite)
Mafic Intrusive Igneous Rock
Quartz
Quartz (SiO₂)
Banded Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Chert (Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Dyed Blue Agate
Silicon Dioxide (SiO2)
Quartz Pebble (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
Amethyst (Tumbled)
Silicon Dioxide (SiO2) with iron impurities
Ferruginous Sandstone (Ironstone)
Ferruginous Sandstone / Limonite-cemented Quartz Sandstone
Quartz Pebble (Milky and Gray)
Quartz (Silicon Dioxide, SiO2)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Red Jasper (Opaque Chalcedony)
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (CaCO3)
Hag Stone
Calcareous sedimentary rock (often Chert, Flint, or Limestone)
Malachite
Copper carbonate hydroxide Cu2CO3(OH)2
Gray Quartz (Tumbled)
Silicon Dioxide (SiO2)
Quartz (vein quartz)
SiO2 (Silicon Dioxide)
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
Copper-bearing Quartz (likely Malachite on Quartz matrix)
Cu2CO3(OH)2 (Malachite) on SiO2 (Quartz)
Chert (Flint variety)
Chert (Microcrystalline or Cryptocrystalline Quartz), SiO2
Dyed Blue Agate (Slab)
Agate (Variety of Chalcedony/Microcrystalline Quartz), SiO2
Hypersthene
(Mg,Fe)SiO3 - Enstatite-Ferrosilite series
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Amethyst Geode
Silicon Dioxide with impurities (SiO2)
Amethyst
Amethyst (Silicon Dioxide - SiO2)
Agate (Chalcedony)
Silicon Dioxide (SiO2)
Specular Hematite (Specularite)
Hematite (Iron(III) oxide) - Fe2O3
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Jasper
Silicon dioxide (SiO2) with impurities
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (Red Jasper variety)
Silicon Dioxide (SiO2)
Sulfur
Native Sulfur (S8)
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Pyrite
Pyrite (Iron Disulfide), FeS2
Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)
Quartz (SiO₂)
Chrysoprase
Nickel-bearing Chalcedony (SiO2 with Ni impurities)
Chert Pebble (Jasper variety)
Microcrystalline Quartz (SiO2)