Corundum Formation example essay topic

"They brought me rubies from the mine, and held them to the sun; I said, 'They are the drops of frozen wine' From Eden's vats that run. ' I look'd again - I thought them hearts of friends, to friends unknown; Tides that should warm each neighboring life are lock'd in sparkling stone. But fire to thaw that ruddy snow, to break enchanted ice, and give love's scarlet tides to flow, - When shall that sun arise?" Ralph Waldo Emerson Precious stones differ greatly from metals and industrial minerals. Next to diamond, corundum is considered to be the most important gem and it is argued that it is more important then emerald. If Corundum is red colored then it is a ruby, all the other colors is called sapphire. Unlike rough gems, which are useless unless of high clarity and cut table sizes, industrial minerals can be processed to extract the desired product.

Where as precious stones is very rear as: "The purest are most rear", thus it is determined the pure the stone the rear it is, thus more expensive it is... Aluminum and Oxygen form Al 2 O 3 - corundum. Aluminum and Oxygen are among planets most abundant elements. So why is the world not awash in corundum, which is simple aluminum oxide?

"The finger of blame must be pointed at the spoiler silicon". Next to oxygen, silicon atoms are more common than any other. "And silicon likes to do it, anyway silicon just can't wait, anytime aluminum and oxygen are free silicon bounds them immediately. Only when free silica is in short supply does corundum stands a chance. "The idea of desilication as a necessary factor is fundamental in understanding corundum formation". In order to understand how corundum is formed, let's examine the makeup of the earth itself before we look directly at corundum deposits.

Several theories exist regarding the earth's formation and evolution of its crust, but evidence favors the idea that our planet accreted from pre-existing solid particles - the same materials which formed our sun and other planets in our solar system. The origin of these particles is another story which will be told later, if necessary. "Heavier elements apparently saw their beginnings in earlier stars, with those stars themselves being products of the births and deaths of other stars. This recycling of matter forms a chain of events that can be traced back to the 'big bang' of popular physics lore". Based on current geologic evidence, the earth has existed as an individual planet for some 4.6 billion years. In the early period, gravity and internally-generated heat slowly reorganized the molten mass into different layers.

While metallic elements and heavier compounds sank towards the core, lighter compounds rose to the surface, eventually cooling into a solid, "non-luminous crustal layer". This crust, a dynamic, constantly moving and fractured skin, surrounds a 13,000-km diameter sphere. The sphere, composed of heavy minerals, was itself organized into two major parts. These divisions are the mantle, a layer about 2900 km think (thought to be made up primary of the mineral olivine), and still-molten core, approximately 7000 km in diameter (theoretically composed mainly of nickel and iron, it is theoretically as by Jules Verne classic notwithstanding, no human has yet to journey anywhere near the center of the earth. ). As time went by the lave cooled down.

There are two categories based up on its formation. that which cooled slowly deep with in the earth ("and so are coarse grained") are termed intrusive, while those which cooled rapidly at the surface ("and so are fine grained") are extrusive. Due to the rapid cooling of extrusive rocks, gem corundum crystals cannot form with in them. However, they often act as a carrier for crystals formed deeper down, which is why many corundum deposits are associated with extrusive igneous rocks. "Corundum has been found in a wide variety of igneous rocks; these include alkaline basaltic lavas.".. Ones corundum is found it has a process of production: Step one: Corundum will be classified to check its quality Step two: Classified corundum will be cleaned by putting it into an acid solution before cutting and polishing Step three: Cut and polished corundum will be heated (one of the methods is it will be heated at the constant temperature of 459 degrees Celsius for a period of 45 min) to make the stone more beautiful and brighter that will push up its quality and price. Step four: Quality of cut and polished precious stones will be carefully controlled and checked before sorting them out.

And finally for a conclusion they are corundum is ready to be sold for collectors or jewelers which will put them into jewelry. Prices for fine three-carat rubies can easily exceed $10,000 per carat. There is plenty more topics which I didn't cover in this essay, as my task was not to write a dissertation but to introduce a cycle of a gemstone corundum. The second important stone after diamond.

Bibliography

Dirham, D.M., Misiorowski, E.B. et al. (1992) Gem wealth of Tanzania.
Gems & Gemology, Vol 28. No. 2, Summer, pp. 180-192; RWHL. Gray, R (1976) The geology of the Fiskenaesset area.
Canadian Gemologist, Vol. 1, No. 2, p. 55; RWHL. Gro mov, A.V. (1993) Rose corundum from the Khitostrov locality of North Karelia.