Agate
Silicon Dioxide (SiO2) - Chalcedony variety
Category
Browse mineraloid (cryptocrystalline quartz) specimens identified by the Rock Identifier community.
Agate
Silicon Dioxide (SiO2) - Chalcedony variety
Cherry Creek Jasper (also known as Red Creek Jasper or Cherry Creek Agate)
Jasper, microcrystalline quartz (SiO₂)
Quartz Pebble (Iron-stained)
Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline Silica (SiO2)
Chert (often called Flint or River Stone)
Chert (SiO2)
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
Agate
Silicon Dioxide (SiO2) - Banded Chalcedony
Petrified Wood
Silicified Wood (SiO2)
Chert (Chert Nodule with Chalky Cortex)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chalcedony with inclusions (Agate/Quartz)
Silicon Dioxide (SiO2)
Banded Carnelian Agate
Var. of Chalcedony (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Agate (specifically, likely a geode slice or nodule)
Agate (a variety of Chalcedony, with chemical formula SiO2)
Chert (Quartz Variety)
Microcrystalline Silica (SiO2)
Agate
Silicon Dioxide (SiO2)
Chert (Jasper/Jasperoid)
Chert (chemically precipitated microcrystalline Quartz, SiO2)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
Jasper (Iron-stained)
Silicon Dioxide (SiO2) with iron oxide inclusions
Chert Nodule in Limestone
Chert (Microcrystalline Quartz, SiO2) and Limestone (Calcium Carbonate, CaCO3)
Druzy Agate (specifically Black Druzy Agate)
Silicon Dioxide (SiO2)
Chert (includes Flint & Jasper)
Chert (Siliceous sedimentary rock, chemical formula SiO2)
Chert (with Quartz Vein)
Chert (Siliceous sedimentary rock, predominantly Microcrystalline Quartz SiO2)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Quartzite
Quartzite (SiO2)
Green Aventurine
Aventurine (a variety of Quartz, SiO2)
Red Jasper
Jasper (Silicon Dioxide: SiO2 with Iron oxide inclusions)
Jasper (Iron-stained Quartz)
Silicon dioxide (SiO2) with iron oxide inclusions
Agate Geode
Banded Chalcedony (Silicon Dioxide, SiO2) with Quartz crystals
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Ocean Jasper
Orbicular Jasper (varietal of SiO2 with impurities)
Chert (specifically Flint or Jasper variant)
Chert (Siliceous rock composed of microcrystalline Quartz, SiO2)
Hag Stone (Banded Chert or Limestone with Borehole)
Microcrystalline Quartz (Chert) or Calciferous Siltstone (CaCO3/SiO2)
Dendritic Agate
Silicon Dioxide with Manganese or Iron Oxide inclusions (SiO2 + Mn/Fe)
Carnelian
Carnelian (a variety of Chalcedony, SiO2)
Micro-crystalline Quartz Pebble (Chert)
Silicon dioxide (SiO2)
Banded Agate (specifically Sardonyx)
Silicon Dioxide (SiO2) - variety of Chalcedony/Quartz
Jasper
Jasper (Silica/Silicon Dioxide, SiO2)
Dendritic Jasper
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Brecciated Jasper
Silicon Dioxide (SiO2) with Hematite and Quartz inclusions
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
Jasper (Yellow/Brown variety)
Silicon Dioxide (SiO2) with iron oxide impurities
Jasper (specifically Picture Jasper or Landscape Jasper)
Silicon Dioxide (SiO2) - Opaque variety of Chalcedony/Quartz