Light Performance And Quality Diamond Jewelry

The one standout quality that diamond jewelry possesses (that makes them so desirable) is their ability to absorb light and disperse it back to the beholder. Humans have always been mesmerized by these light displays for centuries now.

In the jewelry industry, light performance is the description of how well a diamond stone returns the light to the viewer.  The light performance of a diamond tells you how high-quality it is compared to other precious stones. These light properties described in light performance are brilliance, fire, and scintillation.

Brilliance


Brilliance is how we perceive the diamond’s brightness. Normally, brilliance is not just the simple return of the light to the eyes of the beholder coming from the stone’s external and internal facets.  

Brilliance is also more than just the scintillation, the availabilities of light sources and the contrasts. Included here would be the fluctuating variables of an imperfect human perception.

For some, brilliance is the most important feature to consider a diamond’s beauty. This is because once brilliance is compromised, the diamond’s fire and scintillation are both reduced, too. 

Steep diamonds should be set in such a way that the light can enter in the pavilion and is reflected back out to the table (the stone’s top-most facet). Leakages are when a “window effect” is produced and the diamond can be seen through like plain glass.

Scintillation

The idea of scintillation had been thought of as alternating flashes of contrasting dark and brightness produced by facets, caused in turn by the viewer’s movement, the diamond or the illuminating source.

For some experts, defining and measuring scintillation cannot be done accurately, claiming that observations are always personal assessments

Others would define it as a contrast for brilliant white or fiery colored sparkles that appear brighter to the human eye. “Sparkly” things always catch and attract attention. 

Generally, scintillation is the total effect when small flashes of light are seen when the diamond, the light source or the viewer is moved. Consequently, a diamond that is cut and polished that gives off a high level of this quality is considered high in light performance.

There is a common assumption that diamonds with additional facets are more scintillating. (Strangely though, some customers likes better the bolder, blocky scintillation of the Old Mine cuts.)

Fire

The so-called fire in a diamond is its ability to disperse white light into its component colors. These are the spectral colors which are produced when the diamond disperses back the light like an expensive prism.

These flashes of color are more intense and more attractive, though.However, maximum brilliance and maximum fire cannot be observed at the same time, with the same view and at the same point. Brilliance is best seen in well-lighted areas and fire appears better in a point-lit room.  

Whichever quality attracts you to diamond jewelry – brilliance, scintillation, or fire – you certainly are one of those men and woman who had fallen to the magic charms of a very beautiful-looking stone 

     

Why is there a color difference in gold?

When most people think of gold, the image that comes to mind is of a metal with a soft, yellow glow. Indeed, the incomparable golden hue of this precious metal has been part of its appeal for centuries. But for the gold jewelry connoisseur, there are more shades of gold available than just yellow - and in a spectrum of different hues.

While pure gold is yellow in color, colored gold can be developed into various colors. These colors are generally obtained by alloying gold with other elements in various proportions.

For example, alloys which are mixed 14 parts gold to 10 parts alloy create 14-karat gold, 18 parts gold to 6 parts alloy creates 18 karat, and so on. This is often expressed as the result of the ratio, i.e.: 14/24 equals 0.585 and 18/24 is 0.750. There are hundreds of possible alloys and mixtures, but in general the addition of silver will color gold white, and the addition of copper will color it red. A mix of around 50/50 copper and silver gives the range of yellow gold alloys the public is accustomed to seeing in the marketplace. A small amount (0.2%) of zinc can be added to harden the alloy.
The most common grades of gold, in addition to pure 24K, are 22K (92%), 18K (75%), 14K (58%), 10k (41%) and 9K (38%).
Colored golds can be classified to three groups:

• the Au-Ag-Cu system, producing white, yellow, green and red golds; typically malleable alloys
• the intermetallic compounds, producing blue and purple golds, as well as other colors. These are typically brittle but can be used as gems and inlays
• the surface oxide layers, such as black gold; mechanical properties depend on the bulk alloy, and the colored surface is prone to wear

Modern alloys are available in many colors and shades with a listing of popular ones below:

Yellow gold

This is gold in its natural shade. Pure gold (which is always yellow) is too soft for jewelry use. The metals that are mixed with pure gold for strength can also modify the color of gold. It is by far the most common type of gold used in jewelry. Yellow gold used for jewelry is usually alloyed with copper and silver to strengthen it. The warm glow of yellow gold works with virtually any outfit, any skin or body type and any gemstone. How yellow a piece is will depend on its gold content. Generally, 14 karat gold has a brighter yellow than 10 karat gold; 18 karat gold has a deeper yellow than 14 karat gold, and so on.

White gold

White gold has become very fashionable in recent years as many consumers have opted for the cool, contemporary white look over the classic yellow look. A white gold setting can enhance the look of white diamonds and put a modern twist on a traditional standard.

White gold has the same properties as yellow gold, but is mixed with different alloys to give it its white color. Generally, white gold is created by using a nickel or palladium alloy, zinc and copper. White gold is an alloy of gold and at least one white metal, usually nickel, manganese or palladium. Like yellow gold, the purity of white gold is given in karats.

White gold's properties vary depending on the metals and proportions used. As a result, white gold alloys can be used for many different purposes; while a nickel alloy is hard and strong and therefore good for rings and pins, gold-palladium alloys are soft, pliable and good for white gold gemstone settings, sometimes with other metals like copper, silver, and platinum for weight and durability, although this often requires specialized goldsmiths. Sometimes, white gold is plated with an even whiter metal, such as rhodium (a rare member of the platinum family) to enhance its appearance. The term white gold is used very loosely in the industry to describe karat gold alloys with a whitish hue. Many believe that the color of the rhodium plating, which is seen on many commercial pieces, is actually the color of white gold. The term "white" covers a large spectrum of colors that borders or overlaps pale yellow, tinted brown, and even very pale rose. The jewelry industry often improves these off-white colors by rhodium plating.

A common white gold formulation consists of 90 wt.% gold and 10 wt.% nickel. Copper can be added to increase malleability. A white gold setting can enhance the look of white diamonds and put a modern twist on a traditional standard.

About one out of eight people has an allergic reaction to the nickel in some white gold alloys when worn over long periods. A typical reaction is a minor skin rash. Because of this, many European countries do not use nickel white gold. White gold alloys made without nickel are less likely to be allergenic.

Rose gold

Rose gold is a gold and copper alloy widely used for specialized jewelry. It is also known as pink gold and red gold. By alloying just copper with yellow gold, metalsmiths can create gold with a pink, blush-like tint, which experts say lends a soft, flattering effect to the skin. As it was popular in Russia at the beginning of the nineteenth century, it is also known as Russian gold, but this term is now obsolete.

Although the names are often used interchangeably, the difference between red, rose, and pink gold is the copper content – the higher the copper content, the stronger the red coloration. A common alloy for rose gold is 75% gold and 25% copper by mass (18 karat). Since rose gold is an alloy, there is no such thing as "pure rose gold".

A common formulation for red gold is 50% gold and 50% copper.

Green gold

Green gold alloys are made by leaving the copper out of the alloy mixture and just using gold and silver. Green gold was known to Lydians as long ago as 860 BC under the name electrum, a naturally occurring alloy of silver and gold.

This alloy is created by mixing silver, copper and zinc to yellow gold.  It actually appears as a greenish yellow rather than green. Eighteen karat green gold would therefore contain a mix of gold 75% and silver 25% (or 73% gold and 27% silver). Fired enamels adhere better to these alloys.

Grey gold

Grey gold alloys are made by adding silver, manganese and copper in specific ratios to the gold.

To keep the classic appeal of yellow gold but update it with a more modern look, many women are opting for two-tone styles that combine white and yellow goldwithin the same piece. These types of pieces are considered very fashionable and have become particularly popular in bridal jewelry in recent year.
For an even more original look, some women are choosing jewelry which combines three colors of gold (most often yellow, rose and green) within the same piece.

Resources for this article include:

http://en.wikipedia.org/wiki/Colored_gold

http://reviews.ebay.com/GOLD-Difference-in-Karatages-and-Color?ugid=10000000001613063