List of Precious Metals (With Uses) | World | Economic Geography

This article provides a list of four precious metals that are found in the world. Also learn about its uses and distribution.

Metal # 1. Gold (Au):

Gold has been known and used from the earliest days because of its high metallic lustre and its at­tractive yellow-reddish colour. It does not tarnish and can be fashion­ed into beautiful ornaments and jewellery. Gold occurs either in alluvial or placer deposits, as in California and Alaska, or as reefs or lodes underground, as in South Af­rica.

It is difficult to recover but its value makes very lean ores worth working. Poorer ores are treated with chemicals to dissolve out the gold which is then reconstituted, but high-content ores or placer de posits are concentrated in the same way as tin. Gold is a very widespread metal but occurs only in small quan­tities. It usually occurs in native form.

Uses:

(a) Because of its rarity, value and durability (it resists corrosion by air, water and most acids and alkalis), it has always been highly prized as a medium of exchange. It was used as money in actual coins in the past but gold coins are very rare now­adays.

Today the international monetary system is backed by gold. Governments keep a sufficient stock of gold bars or bullion in their treasuries to cover in part the value of the ‘paper money’ which is in everyday circulation.

(b) The major use of gold in indus­try is as jewellery. Gold is one of the most ductile and malleable metals known. Pure gold, however, is too soft to be fashioned into jew­ellery or ornaments and has to be alloyed with, e.g. copper, silver, zinc and nickel. The purity of gold is ex­pressed in terms of carat, pure gold being 24 carats.

(c) Gold has few industrial uses be­cause it is so soft. It is used, however, for a number of minor purposes such as gold tooth fillings, gold-leaf for gilding, making gold paint for crockery and ornamental purposes, fountain pen nibs and for some pur­poses in the chemical industry, e.g. gold compounds are required in photographic materials.

World Distribution:

The greatest producer is South Africa (70%) the mines being con­centrated in the Witwatersrand, Odendaalrus and Lydenbu’rg. Cana­da (5%), Japan (4%), U.S.A. (3%), Papua New Guinea (2%), Austra­lia (2%), Philippines (2%), Zimbab­we (2%) and Ghana (1.5%) are the other major producers, but gold is widely distributed and is found in almost every country in the world.

Metal # 2. Silver (Ag):

Silver is a lustrous white metal, second only to gold as a precious metal though its value is very much less. Its beauty and resistance to corrosion make it desirable for fashioning into jewellery and other ornamental articles, but unlike gold, it tarnishes when it comes into con­tact with sulphur or sulphurous fumes, traces of which are always found in the air. It is, however, very resistant to acetic acid attack and is widely used in making vats for vinegar, beer and industrial acids.

Only one-fifth of the world’s silver is mined as argentite (silver ore) or as native silver. Most is de­rived from the complex ores of lead (galena), copper, zinc and gold. It is usually produced as a by-product of the industrial metals.

Uses:

(a) Silver was once widely used in making coins. The ‘Sterling silver’ coins used in Britain before 1921 were made up of 50% silver with 40% copper for hardening purposes plus some nickel or zinc. But present British coinage has no silver whatso­ever. It is a nickel-copper alloy though in some other countries real silver coins are still in circulation.

(b) Silver is ductile and malleable and, unlike gold, has a fairly wide range of industrial applications. Sil­ver is used in electro-plating, solder­ing and alloying, the manufacture of silverware, and for silver-lined steel tanks and beer vats. Its high thermal and electrical conductivity makes it a possible substitute for copper in the electrical industry, if its price were ever lowered. Silver is used as an electrical conductor in the electrolytic reduction of alu­minium.

(c) Silver compounds such as silver chloride and silver bromide are em­ployed in photography and cinema­tography, now the largest single use of silver. Silver nitrate is used as an antiseptic and silver iodide (in pow­dered form) is used to alter the weather by cloud seeding, because it condenses water vapour easily. Silver salts are used in ‘backing’ mirrors.

World Distribution:

Mexico has long been the chief source of the world’s silver supply. Today it accounts for 14% of world output mainly from Chihuahua and Fresnillo. The U.S.S.R.’s output (13.6%) is almost as large and so is Canada’s (13%) from Kootenay. U.S.A. (12%) mainly from Butte; Peru (9%) from Cerro de Pasco and Australia (8%) are also major pro­ducers. Other producers include Po­land, Japan, Chile and France.

Metal # 3. Platinum (Pt):

Platinum is one of the rarest metals. It is heavy, with a white lustrous appearance and has a very high melting point, 1,550°C to 2,700°C (2,822°F to 4,892°F). Platinum was first discovered in Co­lombia and is often obtained as a by-product in the mining of copper, gold or nickel as in the Sudbury region of Canada.

It is always found with other rare metals allied to the platinum group such as osmium (‘the heaviest metal’, three times the den­sity of iron), palladium (of great medical value), iridium (used in fountain pen nibs) and rhodium (for plating silver to avoid tarnishing). Platinum is highly resistant to cor­rosion.

Uses:

(a) The attractive appearance of platinum has made it popular with jewellers especially in making wed­ding rings and as settings for gem- stones. More than 10% of the world’s platinum goes into jewellery making.

(b) Platinum is hard, inert, has a high melting point and is resistant against both alkalis and acids. It therefore has many industrial ap­plications, especially in the chemi­cal, electrical and metallurgical fields. Platinum powder is employed as a catalyst in the cracking pro­cess of petroleum refining.

It is used for coating the nose- cones of missiles and fuel-nozzles of jet engines to give protection against oxidation or corrosion at extremely high temperatures. Almost half the world’s platinum supply goes to the electrical and electronics industries, e.g. in contact mechanisms of elec­trical systems. Some platinum is also used in the dental and medical fields.

World Distribution:

Canada and the Republic of South Africa lead in production of platinum and its allied metals. The Sudbury district (Canada) and the Rustenburg region (South Africa) have the largest platinum mines, each accounting for nearly 35% of world total.

The Soviet Union is the third major producer, with 28% of world output, mainly from the Nizhni Tagil and Uralets areas of the Urals, as well as deposits in Siberia. Co­lombia now accounts for only 2% world production from the San Juan region. United States has some deposits in California.