Onyx and Sardonyx Beads
Tiger's Eye Beads
Strands of Ornamental Pewter Beads
|Crystals of the mineral cassiterite, the primary ore of the elemental metal tin (Sn). Tin is the principle constituent of pewter.
Pewter is a ductile metal alloy utilizing the metal tin as its major constituent. Pewter artifacts have reportedly been recovered from ancient Bronze Age Egyptian tombs, but pewter was not widely known or used by Western civilizations until the Middle Ages. Although the origins of pewter are lost to history, it is interesting to note that bronze is primarily copper alloyed with lesser amounts of tin, whereas one formulation of pewter is primarily tin alloyed with lesser amounts of copper. Pewter seems to be an inevitable development of bronze technology, very possibly the fortuitous result of some long ago mixing accident.
Initially affordable only by medieval nobility, pewter goods gradually replaced many household items formerly fashioned from wood, leather and clay. By the 15th century the growth of the pewter industry in Europe had spawned trade guilds that regulated quality and commerce in pewter goods, and pewter gradually became affordable to people from less than noble stations in life.
Across the ages the term "pewter" has been used to denote various alloys of tin with other metals in diverse proportions including copper, antimony, bismuth, and lead - the common denominator being tin as the primary constituent. Some historical formulations of pewter contained up to 50% lead, imparting a bluish cast to the metal that rapidly oxidizes to a dark silver-gray color. Modern pewter alloys used to fashion items that come in contact with foodstuffs or the human body are lead free. A typical contemporary formulation for pewter jewelry and coin casting alloy is 94% tin, 5% antimony, and 1% copper. Sterling silver is an alloy of similar proportions, containing 92.5% silver and 7.5% other metals, typically copper. Both pewter and sterling silver employ small percentages of other metals in their formulations to create an alloy that is harder and stronger than pure silver or pure tin alone, and more suitable for making functional objects.
Pewter is often regarded as a less expensive substitute for sterling silver due to its silver-like appearance, but pewter is a fine alloy with its own properties and merits making it an ideal material for decorative and ornamental applications. Tin is not readily oxidized or corroded and is employed as a protective plating on other metals. Because of its low toxicity and resistance to oxidation, tin is used for food packaging, giving "tin" cans their name, which are actually fabricated from steel plated with tin. In addition to being ductile, malleable and oxidation resistant, pewter's significantly lower melting point enables it to be economically cast using vulcanized silicon molds - a factor of consequence impacting the affordability of items cast from pewter using modern techniques.
Pewter is still a relatively expensive material due to being primarily composed of tin, which composes only 2 parts per million of the Earth's crust. Unlike platinum, gold and silver, tin does not occur as an uncombined native element and must be extracted from various mineral ores such as cassiterite. Because Earth's tin ore reserves are estimated to exhaust in 40 years or less at the current rate of global consumption, the value of pewter jewelry and other objects fashioned from pewter are likely to appreciate significantly over the next several decades.
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