How to choose Ruby Posted by Samanmali , Tuesday, December 22, 2009 at 8:34 PM, in

The most important factor in the value of a ruby is colour. The top qualities are as red as you can imagine: a saturated pure spectral hue without any overtones of brown or blue. The word red is derived from the Latin word for ruby, ruber, which is derived from similar words in Persian, Hebrew, and Sanskrit. The intensity of colour of a fine ruby is like a glowing coal, probably the most intensely coloured substance our ancestors ever saw. It is no wonder they ascribed magical powers to these fires that burned perpetually and never extinguished themselves.
Besides colour, other factors that influence the value of a ruby are clarity, cut, and size. Rubies that are perfectly transparent, with no tiny flaws, are more valuable than those with inclusions, which are visible to the eye. Cut can make a big difference in how attractive and lively a ruby appears to the eye. A well-cut stone should reflect backlight evenly across the surface without a dark or washed-out area in the centre that can result from a stone that is too deep or shallow. The shape should also be symmetrical and there should not be any nicks or scratches in the polish. Rubies and other gemstones are sold per carat, a unit of weight equal to one-fifth of a gram. Larger rubies, because they are more rare, will cost more per carat than smaller stones of the same quality.
The Ruby sometimes displays a three-ray, six-point star. These star rubies are cut in a smooth domed cabochon cut to display the effect. The star is most visible when illuminated with a single light source: it moves across the stone as the light moves. This effect, called asterism, is caused by light reflecting off tiny rutile needles, called "silk," which are oriented along the crystal faces.
The value of star rubies and sapphires are influenced by two factors: the intensity and attractiveness of the body colour and the strength and sharpness of the star. All six legs should be straight and equally prominent. Star rubies rarely have the combination of a fine translucent or transparent colour and a sharp prominent star. These gems are valuable and expensive.
The most famous source of fine rubies is Burma, which is now called Myanmar. The ruby mines of Myanmar date back to centuries ago: stone age and bronze age mining tools have been found in the mining area of Mogok. Rubies from the legendary mines in Mogok often have a pure red colour, sometimes described as "pigeon's-blood", although that term is more fanciful than an actual practical standard in the trade today. Myanmar also produces intense pinkish red rubies, which are vivid and extremely beautiful. Many of the rubies from Burma have a strong fluorescence when exposed to ultraviolet rays like those in sunlight, which layers on extra colour. Burma rubies have a reputation of holding their vivid colour under all lighting conditions.

Precious Gem Stone 5 – The Amethyst Posted by Samanmali , at 8:25 PM, in

Amethyst occurs in primary hues from a light pinkish violet to a deep purple. Amethyst may exhibit one or both secondary hues, red and blue.

This precious gem stone is a variety of the common stone quartz. Its typical purplish color is caused by a combination of mineral impurities and crystalline structure. The stone known as burnt amethyst is created by heating the gem, producing a yellowish tint.The ideal grade is called "Deep Siberian" and has a primary purple hue of around 75–80 percent, 15–20 percent blue and (depending on the light source) red secondary hues.

Precious Gem Stone 4 – The Emerald Posted by Samanmali , at 8:19 PM, in

Based on the mineral beryl, the emerald gemstone is pound for pound the most valuable gem stone in the world. The characteristic green color of this precious gemstone is caused by traces of chromium and iron.

Unlike diamond, where the loupe standard, i.e. 10X magnification, is used to grade clarity, emerald is graded by eye. Thus, if an emerald has no visible inclusions to the eye (assuming normal visual acuity) it is considered flawless. Stones that lack surface breaking fissures are extremely rare and therefore almost all emeralds are treated, "oiled", to enhance the apparent clarity. Eye-clean stones of a vivid primary green hue (as described above) with no more than 15% of any secondary hue or combination (either blue or yellow) of a medium-dark tone command the highest prices.

Precious Gem Stone 3 – The Sapphire Posted by Samanmali , at 8:10 PM, in

This precious gem stone is based on corundum. While the blue sapphire gemstone is the best known variety, this precious gem stone comes in a range of colors (fancy sapphires) including pink, orange, purple, yellow, blue and white. In its most pure form, the sapphire is transparent

Blue sapphires are evaluated based upon the purity of their primary hue. Purple, violet and green are the normal secondary hues found in blue sapphires.Violet and purple can contribute to the overall beauty of the color, while green is considered a distinct negative. Blue sapphires with no more than 15% violet or purple are generally said to be of fine quality. Blue sapphires with any amount of green as a secondary hue are not considered to be fine quality. Gray is the normal saturation modifier or mask found in blue sapphires. Gray reduces the saturation or brightness of the hue and therefore has a distinctly negative effect.

Precious Gem Stone 2 - The Ruby Posted by Samanmali , at 7:55 PM, in

Almost as well known as the diamond, the ruby gemstone also rivals the diamond for hardness, ranking nine on the ten point Mohs hardness scale.

Ruby red is associated with passion, vivacity, unbridled love and power. It is a gemstone of exceptional hardness, outstanding brilliance, and dazzling color. Question it is measured to be a royal gem, and was one of the most prized stones in more than one king’s jewel collection. The most well acknowledged measurement of diamond clarity is done by the Gemological Institute of American world (GIA). thru the eyes of ruby.
This precious gem stone is a crystalline compound based on the mineral corundum (aluminum oxide) mixed with the metal chromium, which produces the distinct and signature red color.

Precious Gem Stone 1 - The Diamond Posted by Samanmali , at 7:50 PM, in

Made of a crystalline form of carbon, the diamond is the most well known, and arguably the most admired of the precious gemstones.
The word diamond comes from the ancient Greek word adamas, meaning 'impossible to tame'. The English word 'adamant', which means unbreakable or unyielding, comes from the same root.
Diamond gem stone is the hardest naturally occurring substance, making it the most durable of all precious gem stones. The diamond's complex crystalline structure lends itself to multifaceted shapes, also refracts and disperses ambient light, giving it a brilliance that is virtually unmatched among the precious and semi precious gems.

Precious Gems Posted by Samanmali , at 5:53 AM, in

We have all heard the term,'Precious Gems', before but what, exactly, does it mean?
What makes one thing a precious gem stone and another a semi-precious gem stone or just a rock? The answer to what makes a gem a precious stone is mostly historic and largely arbitrary. 

It was determined by three key factors:

Beauty or appearance: The precious gems historically included only the brilliant faceted gems like the diamond. Other gems, such as jade, ivory and turquoise, though beautiful in their own right, were not considered precious gem stones. 

Usage: The fact that the gem had a special religious or ceremonial significance allowed it to be classed as a precious stone.

Rarity: The law of supply and demand is as old as it is universal. For a gem to be considered a precious stone, it must be historically difficult to come by. This factor has changed over the years as new sources of precious gems are discovered and new mining techniques are developed.

Ceylon Gem Stones Posted by Samanmali , at 5:43 AM, in

Sri Lanka gem stones, (also known as Ceylon gem stones) are highly prized and sought after for their beauty and range of colors. Sri Lanka is a smallish country off of the South Eastern coast of India. 
This tropical nation, about half the size of the State of Ohio in the US, is an important center for the mining of gem stones. In the mining center, located in the hilly interior countryside about 100 miles from the capital city Colombo, sapphires gem stones are still mined by hand in the sandy hillsides.Sri Lanka gem stones are not only beautiful, but are among the largest sapphires mined in the world. 
The star sapphire, so called due to the brilliant star shape that appears on the surface of the gem stone, is among the most valuable of the corundum based gem stones.The star is an optical effect caused by light reflecting off of the crown of the dome shaped stones. The star usually appears as three separate rays forming a six pointed star. In rare cases, a six ray, twelve pointed star can be found. 
Among Sri Lanka gem stones, the star sapphire is one of the most successful exports. The famous -Star of India- which is on display at the American Museum of Natural History in New York, possibly the largest star sapphire in the world, is actually a Sri Lanka gem stone.Though most associate sapphires with the brilliant blue or blue gray varieties, the cornflower blue variety is very highly prized among collectors. 
The Ceylon Gem Stone known as the Ceylon blue sapphire gemstone is an excellent example of a cornflower sapphire.(Prior to the mid nineteen seventies, Sri Lanka was known as Ceylon, and Ceylon Gem Stones are still referred to among gemologists and collectors.). The Sri Lankan blue sapphires are known for having an excellent clarity, a very high transparency, and a very pleasant intensity of color which enable the stones to display a very high in luster.