Chert Pebble
Cryptocrystalline Quartz (SiO2)
Category
Browse organic (if resin) or synthetic (if glass); simulating sedimentary or metamorphic (for natural stones) specimens identified by the Rock Identifier community.
Chert Pebble
Cryptocrystalline Quartz (SiO2)
Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite mica
Polished citrine-like quartz (possibly yellow glass or coated quartz)
Quartz, SiO₂; yellow variety commonly called citrine
Chert (Jasper/Flint)
Microcrystalline Quartz (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Agate
Silicon Dioxide (Chalcedony), SiO2
Jasper or Agate (Chalcedony)
Silicon Dioxide (SiO2) with impurities
Chert
Microcrystalline Quartz (SiO2)
Green Aventurine
Silicon Dioxide (SiO2) with inclusions
Polished green agate/chalcedony
Microcrystalline quartz (SiO₂), likely chrysoprase- or moss-agate-like chalcedony
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions (K(Al,Cr)2AlSi3O10(OH)2)
Tumbled yellow quartz (likely citrine or iron-stained quartz)
Quartz, silicon dioxide (SiO₂), yellow coloration from iron impurities
Jasper / Chert (river tumbled)
Microcrystalline Quartz (SiO2)
Chert
Chert (Microcrystalline Quartz, SiO2)
Green Aventurine
Aventurine Quartz (SiO2 + Fuchsite mica)
Smoky Quartz
Silicon Dioxide (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
River Cobble (Quartzite)
Meta-orthoquartzite
Smoky Quartz
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Citrine (likely Heat-Treated Amethyst)
Silicon Dioxide (SiO2)
Possible chert or weathered quartzite fragment
Microcrystalline quartz (SiO₂), identification uncertain from the photograph
Rounded gray river cobble
Likely fine-grained sandstone, siltstone, or metamorphosed equivalent; exact identification requires a fresh surface and tests
River Jasper (Chert/Chalcedony)
Silicon Dioxide (SiO2) with iron oxide impurities
Smoky Quartz
Silicon Dioxide (SiO2)
Citrine
Silicon dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Green Aventurine
SiO2 (Silicon Dioxide with inclusions of Fuchsite mica)
Citrine Quartz (likely heat-treated)
Silicon Dioxide (SiO2)
Blue Goldstone
Aventurine Glass (SiO2 with Co and metallic inclusions)
Green Aventurine
Quartz containing Fuchsite (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
Smoky Quartz
Silicon Dioxide (SiO2)
Jasper
Silicon dioxide (SiO2) with impurities
Aventurine
Aventurine Quartz (SiO2 with inclusions of Fuchsite)
Chert / Flint Nodules
Cryptocrystalline Quartz (SiO2)
Chert (Nodule)
Chert (Cryptocrystalline Silica, SiO2)
Banded Sandstone (Beach Pebble)
Quartz Arenite Sandstone
Quartz (Milky Quartz / Clear Quartz)
Silicon Dioxide (SiO2)
Blue Sapphire
Corundum (Al2O3)
Quartz (Chert/Chalcedony variety)
Silicon Dioxide (SiO2)
Mica Schist with Quartz
Mica Schist (principally Muscovite and Biotite with Quartz veins)
Chert (Banded)
Microcrystalline Quartz (SiO2)