Thursday, December 16, 2010

Diamond Shapes
The classic diamond is, to most people, a round gem of sparkling white brilliance with a kaleidoscope of dazzling facets to entice the eye.
Yes and no. Diamonds are natural crystals of varying size and shape formed in the earth over millions of years. The traditional round brilliant diamond, though the most popular diamond shape of all, is hardly the whole story.
By the diamond cutter's art these crystals are carved into gems of spectacular and whimsical beauty. A cutter's skill will produce a diamond of the greatest size with the fewest flaws and the most brilliance.
Diamonds come in a variety of shapes. Do not confuse cut with shape. Cut is what determines how well-cut your diamond is, where as diamond shape is the shape it was cut into.

Round Brilliant Diamonds 

This shape has set the standard for all other diamond shapes, and accounts for more than 75% of diamonds sold today. Its 58-facet cut, divided among its crown (top), girdle (widest part) and pavilion (base), is calibrated through a precise formula to achieve the maximum in fire and brilliance.




Oval Diamonds

An even, perfectly symmetrical design popular among women with small hands or short fingers. Its elongated shape gives a flattering illusion of length to the hand.




Marquise Diamonds 

An elongated shape with pointed ends inspired by the fetching smile of the Marquise de Pompadour and commissioned by the Sun King, France's Louis XIV, who wanted a diamond to match it. It is gorgeous when used as a solitaire or when enhanced by smaller diamonds.




Pear Shaped Diamonds

A hybrid cut, combining the best of the oval and the marquise, it is shaped most like a sparkling teardrop. It also belongs to that category of diamond whose design most complements a hand with small or average-length fingers. It is particularly beautiful for pendants or earrings.




Heart Shaped Diamonds 

This ultimate symbol of romance is essentially a pear-shaped diamond with a cleft at the top. The skill of the cutter determines the beauty of the cut. Look for a stone with an even shape and a well-defined outline.



Emerald Cut Diamond

This is a rectangular shape with cut corners. It is known as a step cut because its concentric broad, flat planes resemble stair steps. Since inclusions and inferior color are more pronounced in this particular cut, take pains to select a stone of superior clarity and color.


Princess Cut Diamond

This is a square or rectangular cut with numerous sparkling facets. It is a relatively new cut and often finds its way into solitaire engagement rings. Flattering to a hand with long fingers, it is often embellished with triangular stones at its sides. Because of its design, this cut requires more weight to be directed toward the diamond's depth in order to maximize brilliance.


Trillion Diamonds

This is a spectacular wedge of brittle fire. First developed in Amsterdam, the exact design can vary depending on a particular diamond's natural characteristics and the cutter's personal preferences. It may be a traditional triangular shape with pointed corners or a more rounded triangular shape with 25 facets on the crown, 19 facets on the pavilion, and a polished girdle. It is definitely for the adventurous.


Radiant Cut Diamonds

This square or rectangular cut combines the elegance of the emerald shape diamond with the brilliance of the round, and its 70 facets maximize the effect of its color refraction. Because of its design, this cut requires more weight to be directed toward the diamond's depth in order to maximize brilliance.


Cushion Cut Diamond

An antique style of cut that looks like a cross between an Old Mine Cut (a deep cut with large facets that was common in the late 19th and the early 20th centuries) and a modern oval cut.




The shape of things to come in diamonds has already produced other fanciful and innovative styles such as the flower, cloverleaf, triangle and kite. Nor does it stop there. Some cuts are variations on standard shapes, others spin off the natural crystal formation of the stone, and still others take the idea of shape to revolutionary new heights. Individuality and taste determine the fashion, and the magic of the gem cutter transforms each stone into a unique work of art.






Friday, December 3, 2010

The GIA 4C's grading system

Because diamonds are so valuable, it’s essential to have a universal grading system for comparing their quality. In the 1940s and ’50s, GIA developed the 4Cs and the GIA International Diamond Grading System™ to objectively compare and evaluate diamonds.
The Four Cs of diamond quality will give you a multitude of information about a diamond’s characteristics and value, but they can’t begin to describe one elusive quality – beauty. To do that, you’ll need to experience the diamond with your own eyes.


Carat Weight

Carat weight is the most intuitive of the 4Cs – you expect a larger diamond to be worth more when assigning diamond values.
Diamonds and other gemstones are weighed using metric carats with one carat weighing about the same as a small paper clip, or 0.2 grams. Just as a dollar is divided into 100 pennies, a carat is divided into 100 points which means that a diamond of 50 points weighs 0.50 carats. But two diamonds of equal weight can have very different values depending on the other three characteristics of a diamond’s 4Cs: claritycolor, and cut.
Because even a fraction of a carat can represent a considerable difference in cost when purchasing diamonds, exact precision is crucial. In the diamond industry, weight is measured to a thousandth of a carat and rounded to the nearest hundredth. Each hundredth is called a point (a 0.25 ct. diamond would be called a “twenty-five pointer”). Diamond weights greater than one carat are expressed in carats and decimals. (For instance, a 1.08 ct. stone would be described as “one point oh eight carats,” or “one oh eight.”)

What are "magic sizes"?
Some weights are considered "magic sizes" - half carat, three-quarter carat, and carat. Visually, there's little difference between a 0.99ct. diamond and one that weighs a full carat. But the price differences between the two can be significant.





Color

The Color of the diamond is all about what you can't see.
Diamonds are valued by how closely they approach colorlessness – the less color, the higher the value. Most diamonds found in jewelry stores run from colorless to near-colorless with slight hints of yellow or brown. The only exceptions are the fancy-color diamonds that lie outside of this range.
GIA's diamond color-grading scale is the industry’s most widely accepted grading system. The scale begins with the letter D, representing colorless, and continues, with increasing presence of color, to the letter Z. Diamonds are color-graded by comparing them to stones of known color under controlled lighting and precise viewing conditions.
Many of these color distinctions are so subtle that they are invisible to the untrained eye. But these slight color differences make a very big difference in diamond quality and price.











Clarity


Diamond Clarity refers to the absence of internal inclusions or external blemishes.
Because they are created deep within the earth, most diamonds contain unique birthmarks called inclusions (internal) and blemishes (external). Diamonds with very few birthmarks are rare and, of course, rarity affects a diamond’s value. Using the International Diamond Grading System™, created by GIA, diamonds are given a clarity grade that ranges from flawless (FL) to diamonds with more prominent inclusions (I3).
Every diamond is unique. But none are absolutely perfect even though some come close, even under 10x magnification. Known as flawless diamonds, they are exceptionally rare.
The GIA Clarity Scale contains 11 grades, with most readily available diamonds falling into the VS or SI categories. In determining a clarity grade, GIA considers the size, nature, position, color or relief, and quantity of clarity characteristics visible under 10x magnification.
  • Flawless (FL) - No inclusions or blemishes are visible to a skilled grader using 10× magnification
  • Internally Flawless (IF) - No inclusions and only minor blemishes are visible to a skilled grader using 10× magnification
  • Very, Very Slightly Included (VVS1 and VVS2) - Inclusions are difficult for a skilled grader to see under 10× magnification
  • Very Slightly Included (VS1 and VS2) - Inclusions are clearly visible under 10× magnification but can be characterized as minor
  • Slightly Included (SI1 and SI2)- Inclusions are noticeable to a skilled grader using 10× magnification
  • Imperfect (I1, I2, and I3) - Inclusions are obvious under 10× magnification and may affect transparency and brilliance
What causes inclusions?
Small crystals can become trapped in a diamond when it’s forming. Sometimes as a crystal grows it can develop irregularities in its atomic structure.





Cut

Cut fuels the diamond’s fire, sparkle, and brilliance.
It seems miraculous that the traditional 58 tiny facets in a diamond, each precisely cut and sharply defined, may be only two millimeters in diameter. But without this precision, a diamond wouldn’t be near as beautiful as it is. Without a doubt, the allure of a particular diamond depends more on cut than anything else.
Though extremely difficult to analyze, the cut of a diamond has three attributes: brightness (the total light reflected from a diamond), fire (the dispersion of light into the colors of the spectrum), and scintillation (the light flashes – or sparkle – when a diamond moves).
An understanding of diamond cut begins with the shape of a diamond, with the standard round brilliant dominating the majority of diamond jewelry. All other diamond shapes are known as fancy shapes or fancy cuts and include the marquise, pear, oval, and emerald cuts. Hearts, cushions, triangles, and a variety of other new shapes are also gaining popularity in many forms of diamond jewelry.
As a value factor, though, cut refers to a diamond’s proportions, symmetry and polish. For example, look at a side view of the standard round brilliant. The major components, from top to bottom, are the crown, girdle and pavilion. A round brilliant cut diamond has 57 or 58 facets, the 58th being a tiny flat facet at the bottom of the pavilion that’s known as the culet. The large, flat facet on the top is the table. The proportions of a diamond refer to the relationships between table size, crown angle and pavilion depth. A wide range of proportion combinations are possible, and these ultimately affect the stone’s interaction with light.
In early 2005, GIA unveiled a diamond cut grading system for standard round brilliants in the D-to-Z color range. This system, the product of more than 15 years of intensive research and testing, assigns an overall diamond cut grade ranging from Excellent to Poor.

The different metals used in jewelry

There are several metals used in the creation of fine jewelry. By knowing information about the different metals, their benefits compared with each other and their unique qualities you will be able to make a better and more informed decision about purchasing your jewelry.
The metal types commonly used to make jewelry include gold, platinum, titanium, silver and stainless steel. Metals including rhodium and palladium are also used with jewelry.
Below you will find information about each of these metal types, together with information about which metals are best for particular types of jewelry.

Gold

Gold is the most popular choice for men's and ladies wedding rings and engagement rings. Gold is also very popular in dress rings, earrings, pendants, necklaces and bracelets.
There are several Karats available for gold. The Karat is the gold content of the metal. The Karat measures the proportion of pure gold mixed with other metal alloy to make up the final metal.
The gold Karats normally used in jewelry are 10kt, 14kt and 18kt. The higher the proportion of gold used in the final metal, the more valuable and expensive the metal will be. So all other things being the same, an 18kt ring will be more expensive than a 14kt ring and a 14kt ring will be more expensive than a 10kt ring.

Content of Gold in different Kt's:
10kt gold contains 41.6% pure gold (416 parts per thousand parts).
14kt gold contains 58.5% pure gold (585 parts per thousand parts).
18kt gold contains 75% pure gold (750 parts per thousand parts).
The remainder of the metals is made up of a combination of alloys, different metals which can help to give the metal its unique appearance, such as a different color.

Jewelry is normally stamped with a marking to show the type of gold.
For 10kt gold the stamp will normally be either the number 416,10kt, 10kt or 10K.
For 14kt gold the stamp will normally be either the number 585, 14kt, 14kt or 14K.
For 18kt gold the stamp will normally be either the number 750, 18kt, 18kt or 18K.
The stamps only indicate the Karat of metal. They do not indicate the color of the metal. So for example an 18kt yellow gold ring would have a stamp of 750 as would an 18kt white gold ring.

10kt, 14kt and 18kt gold are each relatively hard and durable metals and are suitable for use in all types of fine jewelry. Gold is also suitable to be used in jewelry that is worn on an everyday basis.
When choosing jewelry, particularly rings, many people consider the hardness and durability of gold to be used in their ring.

Gold colors
Gold is available in several different colors. The most popular is yellow gold, followed by white gold and rose gold, though other gold colors are sometimes also available such as bronze, red and lime gold.
Jewelry can also be made using a combination of different gold colors. These jewelry items are sometimes called two-tone, three-tone or multi-colored gold.

The gold content of yellow gold is measured in the same way it is measured in for example white gold. So an 18kt white gold ring contains 75% pure gold, just as 18kt yellow gold contains 75% pure gold.
The difference in color between yellow, white and rose is determined by the metals used in the alloy mix.
As the color difference is due to the metal components in the alloy mix, the color of yellow gold and rose gold will not chip, fade or wear off with age.
Yellow gold is made by mixing pure gold with alloy metals such as copper and zinc.
Rose gold is made using a mix of pure gold with alloys including copper. The copper provides the rose-reddish color.
White gold is an alloy of gold and some white metals such as silver and palladium.
Traditionally nickel was used in white gold, however, nickel is no longer used in most white gold made today as nickel can cause reactions with some people.

When white gold rings are new they can be coated with another white metal called Rhodium. Rhodium is a metal very similar to platinum and rhodium shares many of the properties of platinum including its white color. The rhodium plating is used to make the white gold look more white. The natural color of white gold is actually a light yellow color. The rhodium is very white and very hard, but it does wear away eventually. To keep a white gold ring looking its best it should be re-rhodium plated approximately each 12 to 18 months. Most local jewelers are able to rhodium plate jewelry for a cost effective price.

Platinum
Platinum is a white metal, but unlike gold it is used in jewelry in almost it's pure form (approximately 105% pure). Platinum is extremely long wearing and is very white, so it does not need to be rhodium plated like white gold does.
Platinum is very dense and heavy metal, so a platinum ring will feel heavier than an 18kt gold ring.
Platinum is, however, significantly more expensive than gold. With all other things being the same, a platinum ring will be approximately twice the price of an 18kt white gold ring.
Platinum is a prestige choice and is often chosen for its sophisticated appeal and popularity amongst the rich and famous.
Platinum is normally not used in the full range of jewelry products due to its higher price.
Platinum is mainly used in ladies engagement rings, ladies wedding rings and men's wedding rings. Platinum can also be used to make dress rings,
though it is not commonly used to make earrings, pendants, bracelets or necklaces.

Palladium
Palladium is a white metal which is has a silver-grey-white color and is similar to platinum. Palladium is one of the metals that is part of the platinum group of metals. The platinum group metals share similar chemical properties.
Palladium is well suited to use with engagement rings and wedding rings.
A few short years ago the price of palladium was actually higher than platinum, however, the price of palladium is now lower than platinum, making it a more affordable option.


Titanium
Titanium is a natural element which has a silver-grayish-white color. Titanium is the hardest natural metal in the world. It is very strong, three times the strength of steel and much stronger than gold, silver and platinum and yet is very light weight. Pure titanium is also 100% hypo-allergenic which means that it if safe for anyone to wear as it will not react to your skin.
Titanium provides several unique factors that make it a good metal for jewelry. It is very strong, more dent, bend and scratch resistant than gold, silver and platinum, is lightweight and importantly offers an exotic array of colors which other metals simply do not.
One factor to consider with titanium is that titanium cannot be soldered, which means that titanium rings cannot normally be resized.
Titanium rings made using pure titanium can normally be cut-off the finger in the event of an emergency, though they are more difficult to cut-off than gold, silver or platinum rings. Aircraft grade titanium rings normally cannot be cut-off in the event of an emergency.
Titanium is popular in earrings and bracelets for both ladies and men.

Silver
Sterling silver is a white-grey colored metal which is less expensive than gold, platinum and titanium.
Silver is a softer metal than gold, titanium and platinum and does not have hardness that the other metals do.
Silver is a popular metal for use in jewelry such as earrings, pendants, bracelets, necklaces and dress rings. It is best used for jewelry that will not be worn every day for an extended period. For that reason it is usually not recommend to be chosen for ladies and men's wedding rings, and is not suitable for ladies engagement rings.
Silver is also more prone to oxidization, sometimes causing the silver to turn black. The silver jewelry can easily be made to look like new again if you use a silver jewelry cleaner (available from most department stores) or if you have your jewelry cleaned by a local jeweler.

Tungsten Carbide
Tungsten carbide, also referred to simply as tungsten, is a very hard, strong and durable metal. It's also quite heavy. Tungsten has a characteristic unique to this special metal - tungsten is highly scratch resistant. Unlike gold, platinum and even titanium, tungsten rings do not scratch with everyday wear like the other metals do.
It is technically possible to scratch tungsten, though only with objects that are harder than tungsten. So that leaves diamonds, sapphires, rubies and ceramic. Though unless you dragged the tip of a loose diamond along the tungsten, the metal will stay scratch resistant.
Having a wedding band that's scratch resistant offers a lot of advantages.
Tungsten always looks new and bright and shiny. Tungsten offers what's referred to as a permanent polish, which means that it doesn't need to be re-polished. So, it doesn't need the polishing maintenance that gold, platinum and titanium rings do.
Tungsten stands up to the wear that even the roughest husbands can dish-out, making it a popular choice for men's wedding rings. Tungsten has an appealing color which almost all men like. The tungsten color is a grey-white color, similar to that of white gold or titanium.
The range of tungsten jewelry is generally more restricted than for other metals.
Tungsten rings cannot be resized (as tungsten can't be cut and re soldered), so it's important to have your finger size accurately measured before buying a tungsten ring.

Stainless steel
Stainless steel is a metal not traditionally used in fine jewelry, though its popularity in dress jewelry is increasing. Stainless steel is a relatively hard and durable metal. It is particularly popular in men's bracelets, necklaces and men's dress rings. The range of stainless steel jewelry is generally more restricted than for other metals.


GIA Diamond Grading Guide: How to Buy a Diamond

GIA - Gemological Institute Of America

A TRADITION OF SCIENCE AND EDUCATION

If you'r in the market to purchase a diamond or a gem one of the first and foremost things you must do is get to know GIA and their science behind it all. If your looking for an unbiased and reliable source of education before you venture out into the diamond world you must visit the Gemological institute of America web site.


Established in 1931, the Gemological Institute of America is the world's foremost authority on diamonds, colored stones, and pearls.

GIA exists to protect all purchasers of gemstones, by providing the education, laboratory, research, andinstruments needed to accurately and objectively determine gemstone quality.

Ensure the public trust
A nonprofit institute, GIA's mission is to ensure the public trust in gems and jewelry by upholding the highest standards of integrity, academics, science, and professionalism through education, research, laboratory services, and instrument development. GIA attained its leadership role through decades of integrity and ingenuity, and everything they do is still driven by this mission.

A Place to Turn to for Unbiased Analysis of Gemstone Quality
GIA is the world's most respected gemological laboratory, entrusted with grading and identifying more gems than any other lab including the Hope, the Taylor-Burton, the De Beers Millennium Star, and the Incomparable. Located in major gem and jewelry centers around the world, GIA laboratories are staffed by expert diamond graders and gemologists, whose work sets the standard for grading practices worldwide.

The bottom line is if you'r in the market to buy your special someone that dream engagement ring make sure it is certified by the people who invented the grading system.