Jumat, 25 Juli 2008

How to Judge the Quality of Your Gemstone’s Setting

Now that you have found the perfect gem, all you need to do is make sure it is displayed well and held securely in place.

To judge the quality of the jewelry setting, pay close attention to details. Is the metal holding the stone even and smoothly finished so it won't catch on clothing? Is the stone held firmly and square in the setting? Is the metal well polished with no little burrs of metal or pockmarks?

Inexpensive jewelry often is very lightweight to give you a bigger look for the money. If a piece is lightweight, pay special attention to the prongs holding the stone: are they sturdy? Do they grip the stone tightly? You won't be happy about the money you saved in gold cost if you lose your stone!

Diamond

Diamond

A scattering of round-brilliant cut diamonds shows off the many reflecting facets.
General
Category Native Minerals
Chemical formula C
Identification
Molecular Weight 12.01 u
Color Typically yellow, brown or gray to colorless. Less often in blue, green, black, translucent white, pink, violet, orange, purple and red.[1]
Crystal habit Octahedral
Crystal system Isometric-Hexoctahedral (Cubic)
Cleavage 111 (perfect in four directions)
Fracture Conchoidal - step like
Mohs Scale hardness 10[1]
Luster Adamantine[1]
Polish luster Adamantine[1]
Refractive index 2.4175–2.4178
Optical Properties Singly Refractive[1]
Birefringence none[1]
Dispersion .044[1]
Pleochroism none[1]
Ultraviolet fluorescence colorless to yellowish stones - inert to strong in long wave, and typically blue. Weaker in short wave.[1]
Absorption spectra In pale yellow stones a 415.5 nm line is typical. Irradiated and annealed diamonds often show a line around 594 nm when cooled to low temperatures.[1]
Streak White
Specific gravity 3.52 (+/- .01)[1]
Density 3.5-3.53 g/cm³
Diaphaneity Transparent to subtransparent to translucent

In mineralogy, diamond is the allotrope of carbon where the carbon atoms are arranged in an isometric-hexoctahedral crystal lattice. Its hardness and high dispersion of light make it useful for industrial applications and jewelry. It is the hardest known naturally-occurring mineral. It is possible to treat regular diamonds under a combination of high pressure and high temperature to produce diamonds (known as Type-II diamonds) that are harder than the diamonds used in hardness gauges.[2] Presently, only aggregated diamond nanorods, a material created using ultrahard fullerite (C60) is confirmed to be harder, although other substances such as cubic boron nitride, rhenium diboride and ultrahard fullerite itself are comparable.

Diamonds are specifically renowned as a material with superlative physical qualities; they make excellent abrasives because they can be scratched only by other diamonds, borazon, ultrahard fullerite, rhenium diboride, or aggregated diamond nanorods, which also means they hold a polish extremely well and retain their lustre. Approximately 130 million carats (26,000 kg) are mined annually, with a total value of nearly USD $9 billion, and about 100,000 kg (220,000 lb) are synthesized annually.[3]

The name diamond derives from the ancient Greek ἀδάμας (adamas) "invincible", "untamed", from ἀ- (a-), "un-" + δαμάω (damáō), "to overpower, to tame". They have been treasured as gemstones since their use as religious icons in ancient India and usage in engraving tools also dates to early human history.[4][5] Popularity of diamonds has risen since the 19th century because of increased supply, improved cutting and polishing techniques, growth in the world economy, and innovative and successful advertising campaigns. They are commonly judged by the “four Cs”: carat, clarity, color, and cut.

Roughly 49% of diamonds originate from central and southern Africa, although significant sources of the mineral have been discovered in Canada, India, Russia, Brazil, and Australia. They are mined from kimberlite and lamproite volcanic pipes, which can bring diamond crystals, originating from deep within the Earth where high pressures and temperatures enable them to form, to the surface. The mining and distribution of natural diamonds are subjects of frequent controversy such as with concerns over the sale of conflict diamonds (aka blood diamonds) by African paramilitary groups.

Jumat, 04 Juli 2008

$1.27 Million Diamond Jeans


Recession? What recession? Rumors abound that the economy is heading down, down, down and consumer confidence is danger of flat-lining. Obviously the analysts and the doomsday sayers have not been thorough in their research. I mean, if people are buying jeans for over $1.2 million, things can’t be that bad – can they?

During London Fashion Week, Secret Circus Clothing Company unveiled a $1.27 million pair of jeans and, by the close of the last show, announced the first pair of diamond-encrusted jeans had been sold.

The jeans are hand-made (obviously) and the back-pocket is embellished with 15 diamonds that include some rather large rocks: a 4.63 marquise diamond, 2 round brilliant six-carater diamonds, one 5.09 carat princess cut gem and a pear-cut diamond weighing in at 5.37 carats. Not forgetting of course 10 single carat diamonds.

Irma Matulionyte modeled them at the label’s launch at London Fashion Week in February, and since then, the brand has stirred up quite a buzz. The owner of the million-buck denims didn’t want to be named, but the company did state the jeans will fit a 27 inch waist. Practicality is, of course, another important consideration when buying jeans with diamonds. Before shoving them in the wash, let’s hope the laundry remembers to use the clasp that will remove the

JEWELRY NEWS

If you’re confused about what jewelry to wear on the golf course and what is considered ‘too much’ – we’ve got one golden rule – keep the jewels off the green – unless they’re on the putter. Confused – don’t be – if you’ve got around $4,000 to spare, your jewelry golfing woes are solved.

A German company, Barth & Sons, have developed a special ‘putter’ for lady golfers who place style and bling above practicality and budget. They’ve developed a custom-built putter with a 24kt gold-plated shaft and a head with crystal inlays (the basic version features pink but you can customize to almost color you want).

The packaging is done in a hand-crafted case of cherry wood and carries a personal engraving on the shaft or a gold plate on the Putter-Inlay if desired. The company also offers several possibilities to further personalize your GoldenPutter, for example, if crystals are a bit too plebian, you can opt for a more expensive model with gems and diamonds instead.

History's Most Famous Blue Gemstone


  • The Star of India -- A 536-carat blue cabochon-cut star sapphire thought to be the largest cut sapphire -- is part of the Morgan-Tiffany Collection in the American Museum of Natural History in New York.

  • The Blue Giant of the Orient -- A 446-carat sapphire from Sri Lanka.

  • The Blue Belle of Asia -- This 400-carat stone from Sri Lanka is the largest sapphire in the British Crown.

  • The Logan Sapphire -- A 423-carat cushion-cut blue from Sri Lanka. The piece was donated to the Smithsonian Institute in Washington, D.C., in 1960 by Mrs. John A. Logan.

  • The Ruspoli -- A 135-carat rhomb-shaped (six facets) blue stone -- resides in France's National Museum of Natural History in Paris. During the 17th century, a Roman prince named Ruspoli sold the sapphire to a salesman, who in turn, sold it to King Louis XIV sometime before 1691. At the time it was the third most prominent gem in the French Crown Jewels.

  • The Star of Asia -- A 330-carat blue cabochon-cut star sapphire -- also resides in the Smithsonian Institute.
  • The Midnight Star -- A 116-carat, black cabochon-cut star sapphire -- is also in the American Museum of Natural History.

  • The Star of Bombay -- A 182-carat, cabochon-cut, blue-violet star sapphire that was bequeathed to the Smithsonian by famous actress Mary Pickford.

  • Catherine the Great's Sapphire -- A 337-carat, faceted oval blue owned by the Diamond Fund of Moscow.

  • Kazanjian Sapphire Carvings -- Huge star sapphires from Australia have been carved into busts of U.S. presidents Lincoln (1,318 carats), Washington (1,056 carats), Eisenhower (1,444 carats), and Jefferson (1,381 carats). A fifth bust of Martin Luther King Jr., has also been carved from an Australian sapphire that originally weighed 4,180 carats and has a finished weight of 3,284 carats. And a sixth bust, Madonna of the Star, was carved from an Australian sapphire weighing 1,100 carats in the rough (525 carats cut). The Kazanjian Foundation of California owns the carvings.

  • Lone Star Sapphire -- This 9,719-carat star sapphire of unknown origin was cut by Dallas cutter John Robinson in 1989.

  • Unnamed Padparadscha (orange) Sapphire -- This 100-carat oval stone from Ceylon (Sri Lanka) resides in the American Museum of Natural History and is considered the world's largest fine Padparadscha.

Sapphire: History's Most Famous Blue Gemstone



Throughout history, sapphire, September's birthstone, has been considered the ultimate blue gemstone. This regal stone is so valued, it is actually the recommended gem for couples celebrating both their fifth and 45th anniversaries.

Although sapphire, a variety of corundum, is most valued in deep blue, the stone comes in a variety of hues, including pink, green, orange, yellow, purple, gray, black, brown, and colorless. Some sapphires even display a six-rayed star pattern when cut into cabochons (domed, unfaceted stones) and are appropriately called star sapphires. The only color you won't find a sapphire in is red -- the red variety of corundum is called ruby.

The word sapphire has roots in several languages: the Arabs called the stone "safir"; the Romans called it "sapphirus" (meaning blue); and the Greeks called it "sappheiros" after the island of sappherine in the Arabian Sea where sapphires were found at that time.

During the Middle Ages, sapphire was thought to represent purity of the soul. It was believed that the stone's color would darken if worn by an "impure" or wicked person. Sapphire was also considered the "Oracle's Stone" and was used to safeguard and foretell the future. The ancients believed the Ten Commandments were written on a sapphire tablet.

The world's finest sapphires used to come from Kashmir, India, but the mines there are now considered depleted. Stones from this region are characterized by their deep cornflower blue color and silky sheen. Incomparable sapphires were dug from one legendary ancient Kashmire mine, but its location is lost in the mists of time -- thus adding to the stones' mystique. Current important sapphire-producing locales include Australia, Myanmar (Burma), Sri Lanka and Thailand. Sapphires also can be found in Cambodia, China, Kenya, Nigeria, Tanzania and the United States (primarily in Montana). Large sapphires are quite rare, and are often given names such as with notable diamonds. Two of the most famous sapphires are part of the British Crown Jewels in the Tower of London. The St. Edwards Sapphire is a rose-cut gem of unknown size set in the finial cross of the Imperial Crown. It derives its name from Edward the Confessor, who wore the stone on a ring during his coronation in 1042. The Stuart Sapphire is a 104-carat oval mounted on the band at the rear of the Imperial Crown. Another famous sapphire associated with British royalty is the one that Prince Charles presented to Princess Diana to seal their engagement. The oval blue, 18-carat sapphire is surrounded by diamonds and set in sterling silver.

Here are a few of history's other notable sapphires. Many are on display in museums and private collections around the world: