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Roger Weller, geology instructor
Platinum and Tungsten
by Sharon Mason
Platinum Vs. Tungsten
When deciding to purchase some sort of jewelry for a loved, the
options are astronomical. There are so many different gemstones and precious
metals to choose from that someone could get lost in all the information
presented. The focus of this presentation will be to better understand the pros
and cons of Platinum and Tungsten, and which would be the best choice for a
significant piece of jewelry.
Platinum, meaning "little Silver," was derived from the Spanish word "platina" and was discovered by Julius Scaliger in 1735. Platinum is a very lustrous, silvery-white metal that occurs in nature with other metal ores in basic igneous rocks and is commonly the byproduct of nickel refining from copper-nickel ores. Platinum is found mainly in South Africa, the Soviet Union, and the United States. It is a soft, malleable metal with a hardness of about 4 on MOHs scale. Platinum's atomic number is 78. It melts at 1772˚C or 3221.6˚F and boils at 3800˚C or 6872˚F. It is unaffected by air and water, however it reacts with hot aqua regia, concentrated phosphoric and sulphuric acids, and molten alkali.
One of the main benefits of Platinum is how resistant it is to corrosion and tarnishing. No matter what temperature it is heated to, it never oxidizes. Another benefit is that Platinum, by itself, is non-toxic and has no known biological role or ill effects on the environment. The best benefit of Platinum is the many uses it has. Platinum has been used to make fine jewelry, surgical tools, laboratory utensils, electrical resistance wires, and electrical contact points. It can also be used as a catalyst in catalytic converters and components in gasoline-fuelled cars' exhaust systems. The glass industry uses Platinum for optical fibers and liquid crystal display glass, usually for laptops and televisions. Platinum bonds have been used as medicine to cure cancer.
One of the disadvantages of Platinum is that it can cause toxicity in the human body when mixed with other chemicals such as selenium. Platinum Salts can cause DNA alterations, cancer, allergic reactions of the skin and mucous membranes, damage to organs and hearing loss.
Tungsten is Swedish for "heavy stone." German smelters found that tin ores containing Tungsten had much lower tin yields than ores without Tungsten, so they named it Wolfram because it seemed to devour the tin "like a wolf." Tungsten was first isolated by two Spanish chemists, the de Elhujar brothers in 1783. It is a grey-white, lustrous metal that most commonly occurs in Scheelite or Wolframite ores. It is found most prevalently in China, Canada, and Russia. It's a harder metal at 7.5 on MOHs scale. Tungsten's atomic number is 74. It has the highest melting point and lowest vapor pressure of any metal. It melts at 3410˚C or 6170˚F and boils at 5530˚C or 9986˚F. It is unaffected by air or water and is barely affected by most mineral acids.
wolframite- photo by Roger Weller
scheelite- photo by Roger Weller
One of the main benefits of Tungsten is its ability to hold up to wear and tear. It has an excellent resistance to corrosion and does not bend easily. It has a low toxicity level and no found biological role in the environment. The most beneficial asset of Tungsten is the many uses it has. Because of its high melting point,
it is often used for filaments in light bulbs. It is also used in electric lamps, electron tubes, television tubes, high speed tools steels, dental drills, and fluorescent lighting. The metal-working, mining, and petroleum industries find many uses for Tungsten. When alloyed with other metals, Tungsten can strengthen them, such as military armor and cutting tools. There are no real disadvantages to Tungsten other than how strong it is, makes it difficult to change it if necessary.
Platinum and Gold are very rare and very expensive. Because of the new economy, consumers have been looking for cheaper replacements for them. Jewelers have begun adding less expensive metals, such as Titanium and Tungsten, to give consumers more price ranges to choose from and keep from going out of business completely. The most recent recession in the United States made Tungsten very popular for many reasons. Tungsten is very durable and virtually scratch resistant. When combined with carbon, it becomes more strong and durable than before. The only element harder would be Diamonds. Especially popular among men, Tungsten Carbide is 10 times stronger than gold and 4 times stronger than Platinum, making it last longer through all the rigorous activities a man can do. It cannot be bent at all like Gold and Silver. The different finishes available for it will not dull or fade over time like Platinum does. And Diamonds, Cubic Zirconias, or other gemstones can be added, just like any other precious metal. The only downside to Tungsten Carbide rings are that they are not resizable. The metal is too tough. However, Tungsten is so inexpensive that replacing the old ring with a new one in the correct size is pocket change.
From the presentation, the consumer can deduce that Tungsten is the better choice for any significant piece of jewelry in the future. It is affordable, durable, and comes with many different options for the wearer.