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Parkesine, the first member of the Celluloid class of compounds and considered the first man-made plastic, is patented by Alexander Parkes. [4] 1869: John Wesley Hyatt discovers a method to simplify the production of celluloid, making industrial production possible. 1872: PVC was accidentally synthesized in 1872 by German chemist Eugen Baumann ...
The first plastic made from synthetic components, it was developed by Leo Baekeland in Yonkers, New York, in 1907, and patented on December 7, 1909. [ 3 ] Bakelite was one of the first plastic-like materials to be introduced into the modern world and was popular because it could be moulded and then hardened into any shape.
Notable early examples of coins include the Lydian Lion coins, Persian daric and siglos, Tong Bei, the dirham and gold dinar. Coins are a major archaeological source of history. Coins convey information about language, administration, religion, economic conditions, and the ruler who minted those coins. [1] Coins were first made of scraps of ...
Many coins throughout history were made of gold, silver and copper. Silver: Gold: Iron: Numerous Chinese cash coins were made of iron, with the first being issued by the Han dynasty in 118 BCE. From 1942 through 1952, some of the Swedish krona coins – such as the 1, 2 and 5 öre – were made of iron. Lead: Most commonly seen in southeast ...
This article focuses mainly on circulating coins; a number of non-circulating commemorative coins have been made in special shapes, including guitars, pyramids, and maps. [1] There is a list with more unusual shapes of non-circulating commemorative coins at the end of this page, that all have been issued officially by various countries.
The name is mostly applied informally to compositions between 20–80% gold and 80–20% silver, but these are strictly called gold or silver depending on the dominant element. Analysis of the composition of electrum in ancient Greek coinage dating from about 600 BC shows that the gold content was about 55.5% in the coinage issued by Phocaea .
5-sol French coin and silver coins – New France; Spanish-American coins- unofficial; Playing cards – 1685-1760s, sometimes officially New France; 15 and a 30-deniers coin known as the mousquetaire – early 17th century New France; Gold Louis – 1720 New France; Sol and Double Sol 1738–1764; English coins early 19th century
In 2012, the Perth Mint produced a 1-tonne coin of 99.99% pure gold with a face value of $1 million AUD, making it the largest minted coin in the world with a gold value of around $50 million AUD. [2] China has produced coins in very limited quantities (less than 20 pieces minted) that exceed 8 kilograms (260 ozt) of gold.