Origins of Materials . Ancient Greek Natural Resources. Mining in Ancient Greece. The Greeks developed extensive silver mines at Laurium , the profits from which helped support the growth of Athens as a city-state .
Miners mining ore (metal).
Washing station to clean mined metals.
Mine tunnels in Ancient Greece.
Ancients Greeks used to make their coins by placing a metal mass between two stamps (moulds) carved with the scenes that would appear in each side of the coin and then they were hitting them with a hammer until the scenes were stamped on the coin. The mass was heated in order to be soft enough for the carving purposes.
The procedure started by melting the metal and then pouring it into round bars. It was then cut in disk shaped pieces which had the same diameter and the same weigh, factors which defined the value of each coin. The discs were turned to coins once having been hit by the workers in order to be stamped. Each coin was created separately thus special care was needed on the part of the worker. The moulds on which the scenes had been carved were made of bronze, iron or brass and as they faded after having transferred their carving to many coins, they had to be replaced especially in the case a large coins number would be needed. The moulds engraving must have been a pricey procedure so sometimes the old ones were copied in order to be used for next generation coins.
The mints were small buildings and the workers used the following tools; a furnace, a scale, a scorp, a punch and a pair of tongs that were used for placing the disc on the anvil where the front side mould had been placed. On other side of the coin a pinch on which the scene had been engraved, was placed. The first side was hit by the worker with a hammer so the coin was pressed from both sides thus the carving was achieved.
In the first years, there were no discs but round metal masses until the round bars were invented.
Debit and Credit cards are made out of a plastic which is man- made or synthetic. The main source of man-made plastic is crude oil.
Petrol, paraffin, lubricating oils and high petroleum gases are bi-products, produced during the refining of crude oil.
These gases are broken down into monomers. Monomers are chemical substances consisting of a single molecule.
A process called Polymerisation occurs when thousands of monomers are linked together. The compounds formed as called polymers.
Combining the element carbon with one or more other elements such as oxygen, hydrogen, chlorine, fluorine and nitrogen makes most polymers.
Crude oil extraction in the Ocean
You may have noticed that dollar bills feel significantly stronger, thicker and smoother than regular paper. Dollar bills are made of a wood pulp that contains Crane brand of paper, cloth including cotton, silk, and linen. This special paper and cloth mixture is known as "rag." Red and blue fibers are cut up into small pieces and inserted into the paper and cloth mixture to create texture and variety in the bill so it is difficult to counterfeit. Dollar bills are printed carefully with ink and are screened for mistakes before their release into the economy.
America has ruled world cotton for about 200 years. Almost nothing else about the global economy has stayed so constant for so long. When you buy a T-shirt that says "made in China," there\'s a pretty good chance it\'s made of cotton that was grown on a farm somewhere in the United States. Plenty of countries in Asia and Africa have natural conditions that are better for growing cotton than those in Texas, where much of the world\'s cotton comes from. But the United States has managed to maintain its supremacy in cotton by investing heavily in technology.
Quarters and dimes are composed of cupro-nickel clad, with a pure copper core, and an outer layer of a 75 percent copper, 25 percent nickel alloy.
Nickels are made from the same 75-25 alloy, and the cent, once a copper coin, is now composed of copper plated zinc. These cents are less expensive for the Mint to manufacture, and at 2.5 grams each, weigh about 20% less than the cent previously minted of 95 percent copper and 5 percent zinc, which weighed 3.11 grams.
Where do metals come from?
Most pure metals, like aluminum, silver and copper, come from the Earth’s crust. They are found in ores or solid materials called minerals, usually occurring in rock, from which the pure metal has to be extracted. The properties of pure metals can be improved by mixing them with other metals to make alloys.