Ammolite is a rare and valuable opal-like organic gemstone found primarily along the eastern slopes of the Rocky Mountains of North America. It is arguably the rarest gemstone on earth, rivaling the rarity of such gemstones as alexandrite and red diamonds. It is made of the fossilized shells of ammonites, which in turn are composed primarily of aragonite, the same mineral that makes up nacreous pearls.
Derinkuyu Underground City is an ancient multi-level underground city in the Derinkuyu district in Nevşehir Province, Turkey. With its eleven floors extending to a depth of approximately 85 m, it was large enough to shelter tens of thousands of people together with their livestock and food stores. It is the largest excavated underground city in Turkey and is part of a network of several underground complexes found across Cappadocia.
The continuous Fly Geyser of Fly Ranch is on private land and began during a 1916 water well drilling that accidentally penetrated a geothermal source.
Lapis lazuli is a relatively rare semi-precious stone that has been prized since antiquity for its intense blue color.
Salar de Uyuni is the world’s largest salt flat at 10,582 square kilometers (4,086 sq mi). It is located in the Potosí and Oruro departments in southwest Bolivia, near the crest of the Andes, and is elevated 3,656 meters (11,995 ft) above the mean sea level. It is covered by a few meters of salt crust, which has an extraordinary flatness with the average altitude variations within one meter over the entire area of the Salar. The crust serves as a source of salt and covers a pool of brine, which is exceptionally rich in lithium. It contains 50 to 70% of the world’s lithium reserves, which has yet to be extracted.
Sima Humboldt is an enormous sinkhole located on the summit of the plateau of Sarisariñama tepui in Venezuela.
A tessellated pavement is a rare erosional feature formed in flat sedimentary rock formations lying on some ocean shores. The pavement bears this name because the rock has fractured into polygonal blocks that resemble tiles, or tessellations. The cracks (or joints) were formed when the rock fractured through the action of stress on the Earth’s crust and subsequently were modified by sand and wave action.
