Chert (often called Flint when dark)
Sedimentary cryptocrystalline quartz (SiO2)
Category
Browse mineral (specifically a cryptocrystalline variety of quartz) specimens identified by the Rock Identifier community.
Chert (often called Flint when dark)
Sedimentary cryptocrystalline quartz (SiO2)
Chert (Pebble)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz (possibly milky quartz)
Quartz (Silica; SiO₂)
Jasper or Chert
Silicon Dioxide (SiO2)
Chert (Common Opal/Jasper variety)
Cryptocrystalline Quartz (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Agate Nodule / Chalcedony
Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Siltstone-Chert mixture)
Microcrystalline Quartz (SiO2)
Blue Sapphire
Corundum (Al2O3 with iron and titanium trace elements)
Green Quartzite (Aventurine-like)
Quartzite (primarily SiO2 with chromium-rich mica or chlorite inclusions)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Granite Pebble (Pink/Orthoclase Granite)
Granite
Pink Granite
Felsic intrusive igneous rock
Dark flint or chert fragment
Microcrystalline quartz (SiO₂), commonly called flint when dark and nodular
Chert (Basanite variety)
Microcrystalline Quartz (SiO2)
Dumortierite Quartz
Al7BO3(SiO4)3O3 (Aluminum borate silicate)
Green Calcite
Calcium Carbonate (CaCO3)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
Sandstone with Iron Staining
Clastic sedimentary rock (primarily SiO2 with Fe2O3)
Polished brecciated jasper
Jasper, an opaque microcrystalline quartz variety (SiO₂), with iron-oxide and clay/mineral inclusions
Carnelian Agate
Chalcedony (SiO2 with Iron Oxides)
Chert (Flint variety)
Microcrystalline Quartz (SiO2)
Tiger's Eye
Silicon dioxide (SiO2) with fibrous inclusions of crocidolite
River Jasper (Chert/Chalcedony mix)
Silicon Dioxide (SiO2) with iron oxide and chlorite inclusions
Quartz (specifically Quartzite or Massive Quartz)
Silicon Dioxide (SiO2)
Rutilated Quartz
Quartz (SiO2) with Rutile (TiO2) inclusions
Chert (specifically Red Chert / Jasper nodule)
Silicon dioxide (SiO2)
Polished brecciated jasper
Jasper (microcrystalline quartz, SiO₂), likely brecciated and iron-stained
Chert / Flint
Microcrystalline quartz (SiO2)
Polished carnelian agate
Chalcedony (microcrystalline quartz), SiO₂, orange iron-oxide variety
Rutilated Quartz
Quartz (SiO2) with Rutile (TiO2) inclusions
Chert (and Limestone)
Chert (consisting of Microcrystalline Quartz, SiO2)
Ocean Jasper
Orbicular Jasper (varietal of SiO2 with impurities)
Jasper and Quartz conglomerate
Silicon Dioxide (SiO2) with iron oxide impurities