Wednesday, May 23, 2012

Platinum

Platinum



Platinum

Called the “King of Metals”, platinum is a very heavy (nearly twice the weight of gold), silver-white metal that is very ductile. Although it is a soft metal, platinum is not easily scratched and is very strong and durable. In fact, as the strongest precious metal used in jewelry, platinum also has a high melting point and good resistance to corrosion and chemical attack. Small amounts of iridium and ruthenium are commonly added to it, to give it a harder, stronger alloy that retains the advantages of pure platinum. The platinum family actually comprises six metals: platinum, palladium, iridium, osmium, rhodium and ruthenium. The six metals are generally found together in nature, with platinum and palladium being the most abundant, and the other four being more rare.
Platinum is also the only precious metal used in fine jewelry that is up to 95 percent pure. Platinum’s subtle beauty and its tendency to not add color of its own, enhances a diamond’s natural brilliance and fire, making it an excellent metal for diamond jewelry settings. Because of its purity, platinum is hypoallergenic, a plus for people with sensitive skin or allergies to certain metals.
History of Platinum
Platinum was first discovered in the alluvial (riverside) deposits of the Rio Pinto, Colombia. The Spaniards called the new metal Platina del Pinto for its resemblance to silver. The world’s most important deposits occur in the Transvaal of South Africa. Other deposits are found in Russia, Finland, Ireland, Borneo, New South Wales, New Zealand, Brazil, Peru and Madagascar.

The Ancient Egyptians and South American Incas prized platinum. France’s Louis XVI proclaimed it the only metal fit for royalty. Legendary jewelers such as Cartier and Faberge created their timeless designs in platinum. The world’s famous diamonds, including the Hope and Koh-l-Noor, are secured permanently in platinum.
Platinum reached its peak of popularity in the early 1900s, when it was the preferred metal for all fine jewelry in America. It dominated the world of jewelry design during the Edwardian era, the Art Deco period and well into the 1930s. At the onset of World War II, however, the U.S. government declared platinum a ‘strategic’ metal and its use in non-military applications, including jewelry, was banned.
Today, platinum is more valuable than gold. Although it is used in many industrial applications, including the automotive industry, platinum jewelry consistently commands higher prices because of its rarity. Also, no reserves of platinum are maintained, as in the case of the federal gold reserve in Fort Knox, KY. The annual worldwide production of platinum amounts to some 160 tons, compared to about 1,500 tons of gold. In fact, in order to produce just one ounce of platinum, about ten tons of ore must be mined.
Buying Guide
When judging the value of platinum jewelry, always ensure that the material is indeed platinum (and not another metal, such as white gold) by checking for the amount of platinum content on the back of the piece. Platinum content is usually marked as “950Pt”, “950 Plat”, or “Plat”. In the United States, in order to be marked “Platinum” or “Plat”, a piece of jewelry must contain at least 95% platinum

Diamond Certification


Diamond Certification

Gold

Gold


Gold



Gold

Gold is a chemical element that, aside from its extraordinary luster, has amazing physical characteristics that make it extremely well suited for use in jewelry making. One ounce (28 grams) of gold can be hammered into 187 square feet of extremely thin sheets called gold leaf. Gold does not tarnish or corrode and it can be re-melted and used again to create new designs.
Because 100% pure gold is too soft for prolonged handling, it is mixed with other metals to give it the durability necessary for jewelry. Most gold used in jewelry is alloyed with silver, copper and small amounts of zinc to produce various shades of yellow gold, or with nickel, copper and zinc to produce white gold. The color of these gold alloys goes from yellow to white as the proportion of nickel increases. Alloying gold with copper creates what is known as pink or rose gold. Alloys with platinum or palladium are also used in jewelry. Since nickel is the most popular alloy used in white gold, it is important to note that some people may be allergic to nickel. If that is the case, 18-Karat gold with a higher percentage of pure gold or platinum settings may be viable alternatives.
The gold content of a piece of jewelry is measured in Karats, which can range from 1 to 24. For example, 14 Karat (14K) gold is 14 parts of gold to 10 parts other metals. The higher the Karat, the greater the gold content. This term should not be confused with “carat”, which measures of the weight of diamonds.
History of Gold
The history of gold goes back at least 6,000 years, with references to it in both Egypt and Mesopotamia. In ancient times, gold was thought to have healing properties when worn or even ingested.

From the time of Christopher Columbus’ discovery of the New World in 1492 to 1600, more than 8,000,000 ounces of gold, or 35 percent of the world’s production came from South America. The New World’s mines–particularly those in Colombia–continued into the 17th and 18th centuries to account for 61 and 80 percent, respectively, of world production. In the 18th century, 48,000,000 ounces were mined.
Russia became the world’s leading producer of gold in 1823, and for 14 years it contributed the bulk of the world’s supply. From 1850 to 1875, more gold was produced in the world than in all the years since 1492, primarily because of discoveries in California and Australia. A significant increase in gold production stemmed from discoveries in Alaska, the Yukon Territory and South Africa. Gold production continued to rise throughout the 20th century, partly because of the improvement in recovery methods and partly because of the continual growth and expansion of South Africa’s gold-mining operations.
In the late 20th century, South Africa, Russia, the United States and Australia accounted for two-thirds of the gold produced annually throughout the world. South Africa alone produces about one-third of the world’s gold.
Buying Guide
Gold pricing is based on a number of factors, including karat amount (called karatage), gram weight, design and craftsmanship. The karatage and gram weight designate how much gold is in a piece, but are not the sole determining price factors. The craftsmanship and level of detail in a piece are also taken into account.
The most critical thing to look for in buying gold jewelry (aside from the style you like!) is the purity of the gold. The higher the gold content, the more valuable it is. The amount of gold in a piece is represented in the karat mark, usually inscribed on the back of the piece (e.g. 24K, 18K, 14K, etc.). The European system uses numbers representing a fraction of 1000, so “750″ would be 75% gold, or the equivalent of 18 Karat. In addition to the karat mark, every piece of gold jewelry should be stamped with a hallmark or trademark of its manufacturer and sometimes its country of origin. In the United States, 14-karat gold, or 583 parts pure gold, is the most common degree of fineness and pieces are marked 14K. Nothing less than 10K can legally be marked or sold as gold jewelry in the 

Diamond Shape 2012

Diamond Shape 2012


Diamond Shape 2012



The most important factors in choosing a diamond stone is deciding on the shape that perfectly matches your style and looks beautiful on you. Your style may guide you to more traditional shapes such as the classic Round, Emerald or Asscher cuts or fancy shapes such as the Marquise, Heart or Pear.
Diamond Shapes
The classic and most popular shape is the Round Brilliant-cut diamond. Its 57 facets bring out the most brilliance, fire and sparkle of all the shapes.
If you’re looking for more contemporary style, consider thePrincess-cut, the second most popular shape. Princess cut diamonds are square or slightly rectangular in shape with pointed corners and an array of intricate facets that increase the diamond’s inherent sparkle.
For a timeless, elegant look, consider the Emerald-cut diamond with its long, lean lines. The rectangular cut, which has a relatively larger open table (top, flat surface) and fewer facets, highlights the clarity of the diamond more than any other shape.
The striking Asscher-cut, often described as a square emerald, evokes an art deco feel from the 1920s and ‘30s. Created at the turn of the 20th century, this shape is now experiencing a resurgence in popularity.
The Radiant-cut is relatively scarce and appeals to those seeking a unique look. This cut combines the geometrical lines of the emerald shape with the sparkling brilliance of the round cut. Its trimmed corners are the signature characteristic of this shape.
As with Asscher-cut diamonds, the Cushion-cut has been popular for more than a century. With a soft and romantic look, the Cushion-cut (or “pillow-cut” as it is often referred to as) has rounded corners and larger facets to increase the stone’s brilliance.
The Marquise shaped diamond delivers drama with its brilliant cut and tapered points at two ends. This diamond, when worn as a ring, creates an elongated, slender look. Cleverly, it also maximizes carat weight, giving the appearance of a larger diamond than a round diamond of the same carat weight.
The Pear shaped diamond resembles a glistening teardrop that combines the soft, rounded end of an Oval shape with the sharp, tapered point of a Marquise-cut. An interesting choice for the multi-faceted personality.
Oval shaped diamonds appeal to those who like their classics with a little edge. Similarly to a classic round diamond, oval diamonds deliver a beautiful brilliance. The elongated shape adds an interesting twist to rings and accentuates the hand to create a slender look.
The fancy-shaped Heart diamond is for the confident woman who is all heart. While sometimes selected for engagement rings, it makes a beautiful choice for pendants in fancy colors such as yellow, pink or red.

جوجل تحتفل بانتخابات الرئاسة المصرية بالصور

جوجل تحتفل بانتخابات الرئاسة المصرية بالصور


مع انطلاق اول يوم من انتخابات الرئاسة المصرية 2012 وهى الاولى بعد الثورة المصرية والاولى ايضا فى الحرية والنزاهه يحتفل محرك جوجل الاشهر عالميا مع المصريين ويضع لوجو بتلك المناسبة فوك شريط البحث الخاص به واللوجو او الصورة عبارة عن حروف كلمة جوجل وكل حرف يؤدى خطوة من خطوات العملية الانتخابية من اول دخولا اللجنة الى التصويت ثم وضع ورقة التصويت فى الصندوق الانتخابى بينما يكتسى كل شىء بعلم مصر نرجو ان تتسم العملية الانتخابية بالروح الاحتفالية دون ان يشوبها ما يعكرها وليصحو كل مصرى غدا ليستنشق عبير الحرية