Sunday 29 December 2013

Most Expensive Emerald Diamond Neck

Queen Marie Jose’s Emerald and Diamond Necklace






This interesting piece of jewelry was once owned by the last royalty of Italy, Queen Marie Jose. She was known for having an extensive collection of jewels including this diamond necklace. 

This necklace contains 50 emeralds and a lot of diamonds. It was created by Van Cleef and Arpels.

Friday 27 December 2013

Most Expensive Sapphire Ring


Sapphire Ring of Princess Diana











Princess Diana is an iconic figure. No wonder the royal jewelry that she wore which is now in the hands of Kate Middleton will be valued at a price approx of $46183. This ring was given by Prince Charles to Lady Diana Spencer on their engagement. Aside from the actual price. This ring is historically significant.


History - 
 Lady Diana Spencer  &  Charles, Prince of wales became engaged in February 1981. Her engagement ring consists of 14 solitaire diamonds surrounding a 12-carat oval Blue Ceylon sapphire set in 18-karat white gold. It was created by jeweler Garrad and cost at the time, 28,000 pounds sterling. Diana's selection of this ring for her engagement to the future King of the United Kingdom resulted in sensation involving curiosity , It is different from the engagement rings of other members of the British Royal Family. 

At the time of her engagement to Charles, featured in Garrard's jewellery collection. Some commentators say she selected it because it reminds her of her mother's engagement ring. 

Princes William and Harry to the palace to select mementos from their mother's possessions. Prince Harry selected the engagement ring, whereas Prince William selected Diana's £18,000 yellow gold Cartier Tank Francoise watch. They eventually exchanged mementos. Prince William decided to give his longtime girlfriend,Catherine Middleton, the engagement ring in October 2010. After the announcement of the engagement of the couple, the engagement ring has become popular selling copies of it.
Middleton eventually had the engagement ring re sized. It was a size H ring. She asked Crown Jewellers G Collins and Sons to attach two platinum studs to it to make it a size I ring. She did not want it to fall from her finger on the day of the royal wedding between her and prince William.






Wednesday 25 December 2013

Ruby

Ruby










Which color would you spontaneously associate with love and vivacity, passion and power? It's obvious, isn't it? Red. Red is the color of love. It radiates warmth and a strong sense of vitality. And red is also the color of the ruby, the king of the gemstones. In the fascinating world of gemstones, the ruby is the undisputed ruler.

For thousands of years, the ruby has been considered one of the most valuable gemstones on Earth. It has everything a precious stone should have: magnificent color, excellent hardness and outstanding brilliance. In addition to that, it is an extremely rare gemstone, especially in its finer qualities.


For a long time India was regarded as the ruby's classical country of origin. In the major works of Indian literature, a rich store of knowledge about gemstones has been handed down over a period of more than two thousand years. The term 'corundum', which we use today, is derived from the Sanskrit word 'kuruvinda'. The Sanskrit word for ruby is 'ratnaraj', which means something like 'king of the gemstones'. And it was a royal welcome indeed which used to be prepared for it. Whenever a particularly beautiful ruby crystal was found, the ruler sent high dignitaries out to meet the precious gemstone and welcome it in appropriate style. Today, rubies still decorate the insignia of many royal households. But are they really all genuine rubies? Read on to find out more!


Only a little bit of chrome (Physical properties) ...

Rubies have a hardness of 9.0 on the Mohs scale of mineral hardness. 
Ruby is α-alumina (the most stable form of Al2O3) in which a small fraction of the aluminium3+ ions are replaced by chromium3+ ions. Each Cr3+ is surrounded octahedrally by six O2- ions. 
This crystallographic arrangement strongly affects each Cr3+, resulting in light absorption in the yellow-green region of the spectrum and thus in the red color of the gem. 
When yellow-green light is absorbed by Cr3+, it is re-emitted as red luminescence this red emission adds to the red color perceived by the subtraction of green and violet light from white light, and adds luster to the gem's appearance. When the optical arrangement is such that the emission is stimulated by 694-nano meter photons reflecting back and forth between two mirrors, the emission grows strongly in intensity. This effect was used by Theodore Maiman in 1960 to make the first successful laser, based on ruby.

All natural rubies have imperfections in them, including color impurities and inclusions of rutile needles known as "silk". Gemologists use these needle inclusions found in natural rubies to distinguish them from synthetics, simulants, or substitutes. Usually the rough stone is heated before cutting. Almost all rubies today are treated in some form, with heat treatment being the most common practice. However, rubies that are completely untreated but still of excellent quality command a large premium.
Some rubies show a three-point or six-point asterism or "star". These rubies are cut into cabochons to display the effect properly. Asterisms are best visible with a single-light source, and move across the stone as the light moves or the stone is rotated. Such effects occur when light is reflected off the "silk" (the structurally oriented rutile needle inclusions) in a certain way. This is one example where inclusions increase the value of a gemstone. Furthermore, rubies can show color changes—though this occurs very rarely—as well as chatoyancy or the " cat's eye " effect. 

Color

Generally, gemstone-quality corundum in all shades of red, including pink, is called rubies. However, in the United States, minimum color saturation must be met to be called a ruby; otherwise the stone will be called a pink sapphire. 
This distinction between rubies and pink sapphires is relatively new, having arisen sometime in the 20th century. If a distinction is made, the line separating a ruby from a pink sapphire is not clear and highly debated. 
As a result of the difficulty and subjectiveness of such distinctions, trade organizations such as the International Colored Gemstone Association (ICA) have adopted the broader definition for ruby which encompasses its lighter shades, including pink.

Natural occurrence-

The Mogok Valley in Myanmar (Burma) was for centuries the world's main source for rubies. That region has produced some of the finest rubies, but in recent years very few good rubies have been found there. The very best color in Myanmar rubies is sometimes described as "pigeon's blood. The most recently found ruby deposit in Myanmar is in Namya (Namyazeik) located in the northern state of Kachin.
Rubies have historically been mined in Thailand, the Pailin and Samlout
Districts of Cambodia, Burma,India, Afganistan and inPakistan. In Srilanka, lighter shades of rubies (often "pink sapphires") are more commonly found.  Ruby deposits were also found in Tanzania,Madagaskar, Vietnam, Nepal,Tajikistan, and Pakistan.

More recently,large ruby deposits have been found under the receding ice shelf of Greenland.

Spinal, another red gemstone, is sometimes found along with rubies in the same gem gravel or marble. Red spinel may be mistaken for ruby by those lacking experience with gems. However, the finest red spinels can have a value approaching that of the average ruby. The color of rubies varies from vermilion to red. The most desired color is "pigeon's blood", which is pure red with a hint of blue. If the color is too pink, the stone is a pink sapphire. The same is true if it is too violet – it is a violet sapphire. The best rubies and star rubies are bright red. Most rubies come from Burma and Thailand.


Treatments and enhancements

Improving the quality of gemstones by treating them is common practice. Some treatments are used in almost all cases and are therefore considered acceptable. During the late 1990s, a large supply of low-cost materials caused a sudden surge in supply of heat-treated rubies, leading to a downward pressure on ruby prices.
Improvements used include color alteration, improving transparency by dissolving rutile inclusions, healing of fractures (cracks) or even completely filling them.
The most common treatment is the application of heat. Most, if not all, rubies at the lower end of the market are heat treated on the rough stones to improve color, remove purple tinge, blue patches and silk. These heat treatments typically occur around temperatures of 1800 °C (3300 °F). Some rubies undergo a process of low tube heat, when the stone is heated over charcoal of a temperature of about 1300 °C (2400 °F) for 20 to 30 minutes. The silk is only partially broken as the color is improved.
Another treatment, which has become more frequent in recent years, is lead glass filling. Filling the fractures inside the ruby with lead glass (or a similar material) dramatically improves the transparency of the stone, making previously unsuitable rubies fit for applications in jewelry. The process is done in four steps:

Factors affecting value-

Diamonds are graded using criteria that have become known as the four Cs, namely color, cut, clarity and carat weight. Similarly natural rubies can be evaluated using the four Cs together with their size and geographic origin.
Color: In the evaluation of colored gemstones, color is the most important factor. Color divides into three components; hue, saturation and tone. Hue refers to "color" as we normally use the term. Transparent gemstones occur in the following primary hues: red, orange, yellow, and green, blue, violet. These are known as pure spectral hues. In nature there are rarely pure hues so when speaking of the hue of a gemstone we speak of primary and secondary and sometimes tertiary hues. In ruby the primary hue must be red. All other hues of the gem species corundum are called sapphire. Ruby may exhibit a range of secondary hues. Orange, purple, violet and pink are possible.

Tuesday 24 December 2013

Emerald

Emeralds






Emeralds are fascinating gemstones. They have the most beautiful, most intense and most radiant green that can possibly be imagined: emerald green. Inclusions are tolerated. In top quality, fine emeralds are even more valuable than diamonds.
The name emerald comes from the Greek 'smaragdos' via the Old French 'esmeralde', and really just means 'green gemstone'.

Emeralds, like all colored gemstone are graded using four basic parameters–the four Cs of Connoisseurship: Color, Cut, Clarity and Crystal. The last C, crystal, is simply a synonym for transparency.

The world of fine emeralds

Colombia continues to be at the top of the list in terms of the countries in which fine emeralds are found. It has about 150 known deposits, though not all of these are currently being exploited. 

The best known names are Muzo and Chivor, where emeralds were mined by the Incas in pre-Columbian times. In economic terms, the most important mine is at Coscuez, where some 60 faces are being worked. 

According to estimates, approximately three quarters of Colombia's emerald production now comes from the Coscuez Mine. Colombian emeralds differ from emeralds from other deposits in that they have an especially fine, shining emerald green unimpaired by any kind of bluish tint. The colour may vary slightly from find to find. This fascinatingly beautiful colour is so highly esteemed in the international emerald trade that even obvious inclusions are regarded as acceptable.

But Colombia has yet more to offer: now and then the Colombian emerald mines throw up rarities such as Trapiche emeralds with their six rays emanating from the centre which resemble the spokes of a millwheel.

Even if many of the best emeralds are undisputedly of Colombian origin, the 'birthplace' of a stone is never an absolute guarantee of its immaculate quality. Fine emeralds are also found in other countries, such as Zambia, Brazil, Zimbabwe, Madagascar, Pakistan, India, Afghanistan and Russia. Zambia, Zimbabwe and Brazil in particular have a good reputation for fine emeralds in the international trade. 

Excellent emerald crystals in a beautiful, deep emerald green and with good transparency come from Zambia. Their colour is mostly darker than that of Colombian emeralds and often has a fine, slightly bluish undertone. 

Emeralds which are mostly smaller, but very fine, in a vivacious, intense green come from Zimbabwe's famous Sandawana Mine, and they often have a delicate yellowish-green nuance. And the famous emerald mines of Colombia currently face competition from right next door: Brazil's gemstone mine Nova Era also produces emeralds in beautiful green tones, and if they are less attractive than those of their famous neighbour it is only by a small margin. 

Brazil also supplies rare emerald cat's eyes and extremely rare emeralds with a six-spoked star. Thanks to the finds in Africa and Brazil, there are more emeralds on the market now than there used to be - to the delight of emerald enthusiasts - .


Color

In gemology, color is divided into three components:hue,saturation& tone. Emeralds occur in hues ranging from yellow-green to blue-green, with the primary hue necessarily being green. Yellow and blue are the normal secondary hues found in emeralds. Only gems that are medium to dark in tone are considered emerald; light-toned gems are known instead by the species name green beryl.

 The finest emerald are approximately 75% tone on a scale where 0% tone would be colorless and 100% would be opaque black. In addition, a fine stone should be well saturated; the hue of an emerald should be bright (vivid). Gray is the normal saturation modifier or mask found in emerald; a grayish-green hue is a dull green hue


Clarity

Emerald tends to have numerous inclusions and surface breaking fissures. Unlike diamond, where the loupe standard, i.e. 10× magnification, is used to grade clarity, emerald is graded by eye. Thus, if an emerald has no visibleinclusion 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", see below) 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. 

This relative crystal non-uniformity makes emeralds more likely than other gemstones to be cut intocabpchons, rather than faceted shapes.


Treatments


Most emeralds are oiled as part of the post-lapidary process, in order to improve their clarity. Cedar oil, having a similar refractive index, is often used in this generally accepted practice. Other liquids, including synthetic oils and polymers with refractive indexes close to that of emerald such as Opticon are also used. 

The world of fine emeralds

Even if many of the best emeralds are undisputedly of Colombian origin, the 'birthplace' of a stone is never an absolute guarantee of its immaculate quality. Fine emeralds are also found in other countries, such as Zambia, Brazil, Zimbabwe, Madagascar, Pakistan, India, Afghanistan and Russia. 

Zambia, Zimbabwe and Brazil in particular have a good reputation for fine emeralds in the international trade. Excellent emerald crystals in a beautiful, deep emerald green and with good transparency come from Zambia. Their colour is mostly darker than that of Colombian emeralds and often has a fine, slightly bluish undertone.

Emeralds which are mostly smaller, but very fine, in a vivacious, intense green come from Zimbabwe's famous Sandawana Mine, and they often have a delicate yellowish-green nuance. 

And the famous emerald mines of Colombia currently face competition from right next door: Brazil's gemstone mine Nova Era also produces emeralds in beautiful green tones, and if they are less attractive than those of their famous neighbour it is only by a small margin.

Brazil also supplies rare emerald cat's eyes and extremely rare emeralds with a six-spoked star. Thanks to the finds in Africa and Brazil, there are more emeralds on the market now than there used to be - to the delight of emerald enthusiasts - . 


Emerald in different cultures, and emerald lore

Emerald is regarded as the traditional birthstone for May, as well as the traditional gemstone for the astrological sign of Taurus , Gemini and sometimes Cancer