Chert (or Chalcedony)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Category
Mineral (Specifically A Variety Of Chalcedony, Which Is A Microcrystalline Quartz)
Browse mineral (specifically a variety of chalcedony, which is a microcrystalline quartz) specimens identified by the Rock Identifier community.
Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)
N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)
Organic (if resin) or Synthetic (if glass); simulating Sedimentary or Metamorphic (for natural stones)
Quartz (likely) or a Quartzite Pebble
Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.
Mineral, specifically a detrital grain
Yellow Quartz (Chert/Chalcedony)
Silicon Dioxide (SiO2) with iron inclusions
mineral
Wood Jasper
Siliceous sedimentary rock (variety of Chert/Chalcedony)
Sedimentary
Granite
Granite (Alkali-feldspar granite)
igneous
Blue Apatite
Apatite group (Ca5(PO4)3(F,Cl,OH))
mineral
Amazonite
Amazonite (KAlSi3O8 – a variety of Microcline, a Potassium Feldspar)
mineral
Quartz (likely macrocrystalline variety)
Quartz (SiO₂)
Mineral
Yellow Banded Agate
Silicon Dioxide (SiO₂)
mineral
Amethyst
Quartz variety; SiO2 (Silicon Dioxide)
Mineral
Brecciated Jasper
Sedimentary Chalcedony (SiO2)
sedimentary
Limestone (specifically Bituminous or Carbonaceous Limestone)
Calcium Carbonate (CaCO3) with Organic Impurities
sedimentary
Banded Agate
Cryptocrystalline Quartz (SiO2)
mineral
Green Aventurine (Carved)
Silicon Dioxide (Quartz variant) with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O(OH)2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Chert (variations include Flint/Novaculite)
Chert (formula: SiO2)
sedimentary
Titanium-coated Metal Cube (Man-made Fidget Toy)
Titanium-anodized or electroplated alloy (e.g., Ti-coated Zinc or Aluminum)
Mineral alternative / Synthetic
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Chalcedony (specifically Common Opal or Agate variant)
Silicon Dioxide (SiO2)
mineral
Quartz (Clear / Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Red Quartzite Slipper Stone
Quartzite (SiO2)
metamorphic
Black Chert
Chert (microcrystalline quartz)
Mineral
Dyed Agate
Silicon Dioxide with artificial pigment (SiO2)
sedimentary
Quartzite Pebble
Quartzite (SiO2)
metamorphic
Citrine Quartz
Citrine (Silicon Dioxide, SiO2)
mineral
Gneiss (specifically a Banded Gneiss pebble)
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Jasper (Green)
Silicon dioxide (SiO2)
Mineral/Sedimentary
Chert (Jasper/Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
River Cobble (likely Sandstone or Siltstone type)
Sandstone or Siltstone (common rock types that form river cobbles)
Sedimentary Rock (specifically a clastic sedimentary rock formed into a cobble)
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and mineral impurities
sedimentary
Chert (Jasper-like)
SiO2 (Cryptocrystalline Quartz)
Sedimentary
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2 as Quartz/Chert/Chalcedony)
sedimentary
Quartz Veined Rock (Likely Graywacke or Quartzite)
Silicon Dioxide (SiO2) veins in Metasedimentary matrix
metamorphic
Green Chalcedony (Green Agate)
Silicon Dioxide (SiO2)
mineral
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
metamorphic
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Tiffany Stone
Bertrandite (Be4Si2O7(OH)2) mixed with Fluorite (CaF2), Opal, and Chalcedony
mineral
Green Aventurine and Clear Quartz
Aventurine (variety of Quartz - SiO2) and Quartz (SiO2)
Mineral