Silver is widely diffused but it rarely found in the native state. It is originally as widespread as Gold or combined with sulphur, arsenic, antimony or chlorine in ores such as argentite (Ag2S), horn silver (AgCl), and pyrargyrite (Ag3SbS3). The principal sources of silver are the ores of copper, copper-nickel, lead, and lead-zinc occurring in nearly all the volcanic rocks. Whereas, Gold remains unaltered by the action of the elements and is often carried long distance from its place of origin Silver on the contrary is only to be found in the rocks where it is originated.
The history of silver is as same as gold history. The first known country is India (Hindustan). Before millions of year ago Indians used silver as a wearing purpose (as an ornaments), as a utensils, as a medicine, as weapons and also used in cloths as a thread.
Pure Silver has a brilliant white colour & is the whitest of all metals. None surpasses it in luster and in hardness it ranges between pure Gold & pure Copper. It is more fusible than Copper & Gold, melting at a bright heat or at 1761 F. It is commonly use for the purpose of alloying Gold in its pure state, but if too much be added it makes the Gold pale.
It is almost as plastic as pure Gold and is too soft to make durable objects that require lightness and stability of form. This defect is overcome by alloying it with a little Copper. An alloy of 925 parts fine Silver & 75 parts Copper is called 925-1000 fine or what is commonly known as sterling Silver. This alloy is used almost universally for jewellery & the best silverware.
The word “Sterling” is the quality mark for the best in Silver. The origin of the term dated back to the 12th century when give free towns banded together in the eastern part of Germany calling themselves the Hanseatic League. They were free to make their own laws and issue their own currency. When trading with British merchants, they paid for the British products with Silver coins. These coins attracted the attention of the Britishers for their consistency of metal & dependability of weights and were, there for referred to as the coins of the Ester lings. In due time after the British adopted the characteristic of these Coins, the metal and the coin became known as fineness & Quality.
Jewelry and silverware are traditionally made fromsterling silver(standard silver), an alloy of 92.5% silver with 7.5% copper. In the US, only an alloy consisting of at least 90.0% fine silver can be marketed as “silver” (thus frequently stamped 900). Sterling silver (stamped 925) is harder than pure silver, and has a lower melting point (893°C) than either pure silver or pure copper.Britannia silveris an alternative,hallmark-quality standard containing 95.8% silver, often used to make silver tableware and wrought plate. With the addition ofgermanium, the patented modified alloyArgentium Sterling silveris formed, with improved properties, including resistance tofire scale.
Sterling silver jewelry is often plated with a thin coat of 999fine silver to give the item a shiny finish. This process is called “flashing”. Silver jewelry can also be plated withrhodium(for a bright, shiny look) or gold.
Traditionally, silversmiths mostly made “silverware” (cutlery, tableflatware, bowls, candlesticks and such). Only in more recent times has silversmithing become main work in jewelry, as much less solid silver tableware is now handmade.
Silver can be alloyed with mercury, tin and other metals at room temperature to makeamalgamsthat are widely used for dental fillings. Some electrical and electronic products use silver for its superior conductivity, even when tarnished.
Some manufacturers produce audio connector cables, speaker wires, and power cables using silver conductors, which have a 6% higher conductivity than ordinary copper ones of identical dimensions, but cost very much more. Though debatable, many hi-fi enthusiasts believe silver wires improve sound quality.
Small devices, such as hearing aids and watches, commonly usesilver oxide batteriesdue to their long life and high energy to weight ratio. Another usage is high-capacitysilver-zincand silver-cadmiumbatteries.
Mirrorswhich need superior reflectivity for visible light are made with silver as the reflecting material in a process calledsilvering, though common mirrors are backed with aluminum. Using a process calledsputtering, silver (and sometimes gold) can be applied to glass at various thicknesses, allowing different amounts of light to penetrate.
Because silver readily absorbs freeneutrons, it is commonly used to makecontrol rodsto regulate thefission chain reactioninpressurized water nuclear reactors, generally in the form of analloycontaining 80% silver, 15%indium, and 5%cadmium.
Silver ions and silver compounds show a toxic effect on some bacteria, viruses, algae and fungi, typical for heavy metals likeleadormercury, but without the high toxicity to humans normally associated with these other metals. Its germicidal effects kill many microbial organismsin vitro, but testing and standardization of silver products is difficult.
Silver has been used for thousands of years for ornaments and utensils, for trade, and as the basis for many monetary systems. Its value as a precious metal was long considered second only to gold. The word “silver” appears inAnglo-Saxonin various spellings such asseolforand siolfor.