Amethyst (Tumbled)
Silicon Dioxide (SiO2 with iron impurities)
mineral
Category
Organic (Non Rock)
Browse organic (non rock) specimens identified by the Rock Identifier community.
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Blue Chalcedony
Silicon Dioxide (SiO2)
mineral
Carnelian Agate Nodule
Silicon Dioxide (SiO2) - Carnelian Chalcedony
mineral
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Banded Quartz
Silicon Dioxide (SiO2)
mineral
Amethyst (Rough)
Silicon Dioxide with iron impurities (SiO2)
mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Blue Chalcedony (likely dyed Agate)
Silicon Dioxide (SiO₂)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Chalcedony
Chalcedony (SiO2)
mineral
White Quartzite
Quartzite (primarily SiO2)
metamorphic
Carnelian (Red Chalcedony)
Silicon Dioxide (SiO2)
mineral
Jasper (Iron-stained Quartzite/Chert)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Agate (Moss or Lake Superior type)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
mineral
Unakite
Epidotized Granite
metamorphic
River Stone (Basalt Porphyry)
Porphyritic Basalt
igneous
River Pebble (Likely Quartzite or Chert)
Quartzite (primarily SiO2)
metamorphic
Obsidian
Volcanic Glass (70-75% SiO2)
igneous
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Chalk
Carbonate rock (mainly CaCO3)
sedimentary
Sandstone
Arenite (SiO2 principal)
sedimentary
Chalcedony (Agate)
Silicon Dioxide (SiO2)
mineral
Sandstone
Arenite (primarily SiO2)
sedimentary
Basalt
Extrusive mafic igneous rock
igneous
Druzy Quartz Geode (Vug)
Silicon Dioxide (SiO2)
mineral
Sandstone (likely Calcareous or Quartz-rich)
Arenite (SiO2 based typically)
sedimentary
Sandstone (Quartzose Sandstone)
Arenite (SiO2 principal component)
sedimentary
Sandstone (Stream-rounded)
Arenite (SiO2 based)
sedimentary
Pumice
Pumice (Vesicular Rhyolite/Andesite)
igneous
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Conglomerate
Conglomeratic Sandstone / Sedimentary Breccia
sedimentary
Chalcedony (Common Agate)
Silicon Dioxide (SiO2)
mineral
Sandstone
Arenite (SiO2 primarily)
sedimentary
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Sandstone
Arenite
sedimentary
Sandstone (Quartzite-rich Pebble)
Arenite (primarily SiO2)
sedimentary
Ferruginous Sandstone
Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone (likely Arkose)
Arenite (composed mainly of SiO2 with Feldspar)
sedimentary