Banded Agate (Geode Fragment)
Silicon Dioxide (SiO2) - Variety Agate
Category
Browse sedimentary rock (cryptocrystalline quartz) specimens identified by the Rock Identifier community.
Banded Agate (Geode Fragment)
Silicon Dioxide (SiO2) - Variety Agate
Chert (Yellow Jasper/Flint)
Microcrystalline Quartz (SiO2)
Green Jasper with Agate Banding
Silicon Dioxide (SiO2) with impurities of ferrous silicate or chlorite
Jasper and Chalcedony Nodule
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Pebble (likely Quartz or Chert)
SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.
Petrified Wood
Silicified Wood (SiO2)
Chert (Jasper/River Rock)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily Chalcedony or Quartz, SiO2)
Chert (Flint variety)
Chert (SiO2)
Polished brecciated jasper
Jasper (microcrystalline quartz, SiO₂), likely brecciated and iron-oxide stained
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
Red jasper pebble
Jasper, microcrystalline quartz (SiO₂) colored chiefly by iron oxides
Agate
Silicon Dioxide (Chalcedony), SiO2
Petrified Wood
Silicified Wood (primarily SiO2)
Polished brecciated jasper (likely ocean jasper or orbicular jasper)
Microcrystalline quartz/chalcedony (SiO₂) with iron-oxide and other mineral inclusions
Tumbled yellow-orange jasper
Microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides
Chert (often found within Limestone)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Polished red jasper
Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides
Banded Agate (Banded Chert / Jasper)
Silicon Dioxide (SiO2)
Agate
Silicon Dioxide (Chalcedony), SiO2
Polished brown jasper
Jasper, an opaque microcrystalline variety of quartz (SiO₂), likely iron-rich brecciated or orbicular jasper
Ironstone / Hematite Concretion
Iron oxide / Fe2O3
River Chalcedony / Agate
Chalcedony (Silicon Dioxide, SiO2)
Picture Jasper
Silicon dioxide (SiO2)
Red Jasper Pebble
Microcrystalline Quartz (SiO2)
Agate (specifically, a slice of a Blue Lace or Chalcedony Agate nodule)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Chert (Weathered)
Chert (Microcrystalline Quartz, SiO2)
Jasper with Quartz Veining
Silicon Dioxide (SiO2) - Opaque cryptocrystalline variety of Quartz
Polished petrified wood (agate/chalcedony replacement)
Silicified wood, chiefly microcrystalline quartz (SiO₂), often with iron-oxide coloration
Chert Pebble with Quartz Veins
Microcrystalline Quartz (SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (and Jasper blend)
Chert (Microcrystalline Quartz, SiO2)
Brecciated Jasper
Silicon dioxide (SiO2) microcrystalline quartz breccia
Banded Chert (River Siltstone)
Microcrystalline Quartz (SiO2)
Chert with Desert Varnish
Cryptocrystalline Quartz (SiO2) with Manganese/Iron oxide coating
Chert (Chalcedony/Agate variety)
Microcrystalline Quartz (SiO2)
Yellow Chert Pebble
Microcrystalline Quartz (SiO2)
Chert Breccia
Microcrystalline Quartz (SiO2) Breccia
Chert (Nodular)
Chert (Microcrystalline Quartz, SiO2)
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement) SiO2
Red jasper (likely iron-rich chert)
Microcrystalline quartz (SiO₂) colored by hematite/goethite