Gold Essay Example | Topics and Well Written Essays - 750 words

Gold - Essay Example Gold’s actual discovery remains only known to the ancients (Mineral Zone, 1). Gold is the seventy ninth element on the periodic table and it has symbol AU which is derived from the Latin word â€Å"Aurum† which means shining dawn. â€Å"It occurs mostly in the native state, remaining chemically uncombined except with selenium, tellurium and possibly bismuth. The elements only naturally occurring isotope is gold-197† (Gold.yabz, 1). Deposit of gold with high amounts of gold: hydrothermal veins, where it is associated with pyrite (fools gold) and quartz; and consolidated and unconsolidated placer deposits that are derived from the weathering of gold-bearing rocks. Gold is considerably associated with differential amounts of silver; with electrum being the most common and naturally occurring gold-silver alloy, with trace amounts of copper and other metals. Geographically electrum is found in Western Anatolia, present day Turkey (Gold.yabz, 1). Occurrence of gold-bearing rocks rich in it, is unusual, which is to say gold ores are not so (common. In seawater gold occurs to the extent of 5 to 250 parts by weight to 100 million parts of water. Presently gold quantity of gold in seawater is estimated to be 9 billion metric tons. Its deposits are widespread in low concentrations all over the continents. Gold deposits are found in two types; lode deposits which is mined through conventional mining methods and placer deposits found along stream beds caused by the erosion of the lode deposits. Its abundance is estimated to vary in concentrations in igneous rocks on the continent varying between .001 to 0.004 ppm. Since discovery, 165,000 tons of it has been mined. Gold is commonly used in ornaments and jewellery (USGS, 1). This is because the metal is highly malleable as it can form very thin sheet of about 0.000005 inches in size, so it served the purpose. Additionally as it is a noble metal, it

Construction Related topic Essay Example | Topics and Well Written Essays - 500 words

Construction Related topic - Essay Example In an online source, Wikipedia, it states that "Before this time bricks were generally made as close as possible to their point of intended use (it has been estimated that in England in the eighteenth century carrying bricks by horse and cart for ten miles over the poor roads then existing could more than double their price)." Woody Harrelson says in the movie Indecent Proposal (1993), "A common, ordinary brick wants to be something more than it is." This statement conforms to the recent developments organised by the Brick Development Association (BDA), who represents the UK brick industry, looks for new and modern ways on how to utilise effectively this versatile construction material. BDA is the working group in developing the codes of practice for clay masonry and pavers units. Continues efforts are employed in exploring new products and mixtures for brick by the group since brick is one of Europe's most popular building materials remain intact. Many researches were conducted to explore different mixtures for brick and managing recycled brick. Recycled clay brick aggregates for use in concrete is one of the by-products of bricks that were experimented.