Boron is a relatively rare element in the Earth's crust, representing only 0.001%. The worldwide commercial borate deposits are estimated as 10 million tonnes. Turkey and the United States are the world's largest producers of boron. Turkey has almost 72% of the world’s boron reserves. Boron does not appear on Earth in elemental form but is found combined in borax(sodium borate, sodium tetraborate, or disodium tetraborate), boric acid, colemanite(CaB3O4(OH)3·H2O) , kernite(Na2B4O6(OH)2·3H2O), ulexite(NaCaB5O6(OH)6•5(H2O)) and borates. Boric acid is sometimes found in volcanic spring waters. Ulexite is a borate mineral; it is a fibrous crystal where individual fibers can guide light like optical fibers.
Economically important sources of boron are rasorite (kernite) and tincal (borax ore). They are both found in the Mojave Desert of California, but the largest borax deposits are in Central and Western Turkey including the provinces of Eskişehir, Kütahya and Balıkesir.
Neon is actually abundant on a universal scale: the fifth most abundant chemical element in the universe by mass, after hydrogen, helium, oxygen, and carbon (see chemical element). Its relative rarity on Earth, like that of helium, is due to its relative lightness, high vapor pressure at very low temperatures, and chemical inertness, all properties which tend to keep it from being trapped in the condensing gas and dust clouds which resulted in the formation of smaller and warmer solid planets like Earth.
Neon is monatomic, making it lighter than the molecules of diatomic nitrogen and oxygen which form the bulk of Earth's atmosphere; a balloon filled with neon will rise in air, albeit more slowly than a helium balloon.
Mass abundance in the universe is about 1 part in 750 and in the Sun and presumably in the proto-solar system nebula, about 1 part in 600. The Galileo spacecraft atmospheric entry probe found that even in the upper atmosphere of Jupiter, the abundance of neon is reduced (depleted) by about a factor of 10, to a level of 1 part in 6,000 by mass. This may indicate that even the ice-planetesimals which brought neon into Jupiter from the outer solar system, formed in a region which was too warm for them to have kept their neon (abundances of heavier inert gases on Jupiter are several times that found in the Sun).
Neon is a monatomic gas at standard conditions. Neon is rare on Earth, found in the Earth's atmosphere at 1 part in 65,000 (by volume) or 1 part in 83,000 by mass. It is industrially produced by cryogenic fractional distillation of liquefied air.
Calcium is not naturally found in its elemental state. Calcium occurs most commonly in sedimentary rocks in the minerals calcite, dolomite and gypsum. It also occurs in igneous and metamorphic rocks chiefly in the silicate minerals: plagioclase, amphiboles, pyroxenes and garnets.
- ↑ Argust, Peter (1998). "Distribution of boron in the environment". Biological Trace Element Research 66 (1–3): 131–143. doi:10.1007/BF02783133. PMID 10050915.
- ↑ Woods, William G. (1994). "An Introduction to Boron: History, Sources, Uses, and Chemistry". Environmental Health Perspectives 102, Supplement 7, http://www.ehponline.org/realfiles/members/1994/Suppl-7/woods-full.html. Retrieved on 20 September 2008.
- ↑ Kostick, Dennis S. (2006). "Mineral Yearbook: Boron" (PDF). United States Geological Survey. Retrieved on 2008-09-20.
- ↑ "Mineral Commodity Summaries: Boron" (PDF). United States Geological Survey (2008). Retrieved on 2008-09-20.
- ↑ "Developments in the Economic Sector (of Turkey)". Turkish government. Retrieved on 2007-12-21.
- ↑ Simmons, R.; Ahsian, N.; Raven, H. (2007). The Book of Stones: Who They Are and What They Teach, North Atlantic Books. pp. 421–422. ISBN 1556436688.
- ↑ Kistler, R. B. (1994). "Boron and Borates". Industrial Minerals and Rocks (Society of Mining, Metalurgy and Exploration, Inc.): 171–186, http://kisi.deu.edu.tr/cahit.helvaci/Boron.pdf.
- ↑ Zbayolu, G.; Poslu, K. (1992). "Mining and Processing of Borates in Turkey". Mineral Processing and Extractive Metallurgy Review 9 (1–4): 245–254. doi:10.1080/08827509208952709.
- ↑ Kar, Y.; Şen, Nejdet; Demİrbaş, Ayhan (2006). "Boron Minerals in Turkey, Their Application Areas and Importance for the Country's Economy". Minerals & Energy - Raw Materials Report 20 (3–4): 2–10. doi:10.1080/14041040500504293.
- ↑ Gallagher, R.; Ingram, P. (2001). Chemistry for Higher Tier, University Press. ISBN 9780199148172, http://books.google.com/books?id=SJtWSy69eVsC&pg=PA96.
- ↑ Morse, David (January 26, 1996). "Galileo Probe Science Result". Galileo Project. Retrieved on February 27, 2007.
- ↑ Cite error: Invalid
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