Emerald

Emerald

Emerald is the green variety of the mineral beryl. Other gemstone color varieties that belong to beryl include aquamarine, morganite, heliodor, and goshenite. Other colors of beryl are simply referred to by their color, such as red beryl. The wonderful green color of emerald is unparalleled in the gem kingdom. Emerald's precious green color is caused by small amounts of chromium and enhanced by traces of iron. Unlike other beryls, emeralds often contain inclusions and other flaws. These flaws are not looked on as negative aspects for emerald like they would be for other gemstones. Indeed, these flaws are considered part of the character of the stone and are used to assure the purchaser of a natural stone. However, fractures and inclusions are so common in emeralds that their toughness is affected - emeralds tend to break more easily than other beryls.

Nearly all emerald gemstones have been treated to improve their appearance. Historically, gems were "oiled" which filled the cracks and veils with a transparent oil, effectively hiding the flaw. Unfortunately, oils tend to evaporate over the years (and they may be removed with detergents) so that oil-treated emeralds tend to look worse over time. Luckily, the treatment may be repeated to good effect. In recent times, the cracks are filled with a permanent epoxy so evaporation of oil is not an issue.

In any case, you should expect an emerald to be treated. Note that oil (or polymer resin) treatments are considered acceptable in the gem trade, unless colored oils are used to change the color. For fine gemstones, treatments are required to be disclosed by the U.S. Federal Trade Commission.

Emerald is mined around the world, although certain localities provide the best gemstones. Columbia is especially notable, producing fine deep-green emeralds of excellent transparency. Brazil and Pakistan are other notable sources of fine emeralds

This is a piece of emerald, that was displayed in Hong Kong, last month. This 536-kg emerald is 125 cm long, 55 cm high and 78 cm wide. It huge piece of emerald is believed to be one of the largest and heaviest emeralds in the world. (Photo Credit: Xinhua Photo)

It is one of the largest gem-quality emeralds in the world, The stone resides in the New York Museum of Natural History.

The 1759-carat Guinness Emerald Crystal. The stone was found at the Coscuez in Columbia and is one of the largest gem-quality emerald crystals in the world

Sapphire

Sapphire

Sapphires and Rubies are members of the same crystal mineral family called Corrundum. Corrundum with any color except red, is called Sapphire. Sapphires are richest in colors compared to all other gemstones. They are rare and very durable. All of these qualities make sapphires precious gemstones. Blue Sapphire and Yellow Sapphire are the most sought after in sapphires. Pink sapphire has become more rarer then blue sapphires because of increasing demand for these gems. There are also the Green Sapphire, Orange sapphire and Golden Sapphires. There are many other colors but a very interesting sapphire is the Padparadscha Sapphire because of its beautiful pinky orange color.The finest sapphire color is rich, velvety cornflower blue. This is called "kashmir" out of deference to the traditional source of the finest quality. Today, however, the Kashmir area of India is not generally mined because of its physical inaccessibility. Most current production comes from Sri Lanka, Burma, Thailand, Montana, Australia and Africa.

Star sapphire

Padparadscha Sapphire

Variety of Blue sapphire

Ruby

Ruby

Is distinguished and known by all for its fiery red color. Beside for its color, it is a most desirable gem due to its hardness, durability, luster, and rarity. Transparent rubies of large sizes are even rarer than diamonds. Transparent, flawless rubies exceed all other gems in value. (except for deeply colored "fancy diamonds"). Rubies must be transparent to possess gem value.Opaque or semi-opaque rubies have little value, even if they display asterism.Ruby is a red variety of the mineral corundum. Sapphire, the other gem variety of corundum, encompasses all colors of corundum aside from red. In essence, ruby is a red sapphire, since ruby and sapphire are identical in all properties except for color. The color of ruby ranges from bright red to dark reddish-brown. The most preferred color is a deep blood red with a slightly bluish hue. Such ruby is known as "Burmese Ruby" or "Pigeon's Blood Ruby". Ruby from Burma is famous for its exceptional coloring. However, Burmese ruby rarely exceeds several carats; large flawless Burmese rubies can be worth millions of dollars. Most rubies on the market are from Thailand, and these rubies have a brownish hue. They can be heat-treatmed to improve color. Heat-treating a ruby can also increase its transparency by removing tiny internal flaws.

VARIETIES

Star Ruby - Ruby displaying

asterism

Cat's Eye Ruby - Ruby exhibiting cat's eye effect

Verneuil

Burmese Ruby - Ruby with
exceptional color (usually but not necessarily from Burma)

Burma Ruby - Synonym of Burma ruby (above)

Pigeon's Blood Ruby - Blood-red ruby with a hint of blue

Rare Diamonds

What is Diamond

Diamond is a colourless exceptionally hard mineral (but often tinted yellow, orange, blue, brown, or black by impurities), found in certain igneous rocks esp. the kimberlites of South Africa. It is used as a gemstone, as an abrasive, and on the working edges of cutting tools. Composition: carbon. Formula: C. Crystal structure: cubic. Name derived from the Greek adamas meaning invincible. Relative density 3.50- 3.52. Cleavage eminent along octahedral faces. Fracture conchoidal. Tenacity brittle. Lustre brilliantly adamantine. Refractive index 2.417- 2.419. Birefringence and pleochroism: none (cubic). Dispersion strong 0.044. Diamond crystals form as cubes, octahedra , the most common gem form, and dodecahedra. Colourless to yellow diamonds which have a strong absorbtion line in the violet end of the spectrum are members of the Cape series.

Where is it found?

The most famous diamond bearing country is South Africa. The first diamond was reported in 1866. By 1869 an 83.5 carat diamond had been found and was named The Star of Africa. It was subsequently cut into a pear shape brilliant weighing 47.74 carats. The Golconda area of Southern India has been the source of some famous diamonds such as the Koh-i-nor (mountain of light 186cts cut to 108.92 cts and now in the Tower of London) and Jehangir. Diamond is widespread in Brazil, most stones being small but of good gem quality. Alluvial diamonds have been found in most states of the USA. White and fancy coloured diamonds such as pinks and pinkish browns are mined at Argyle in North Western Australia. Other important producers are Russia, now the fourth largest producer, and China.

Yellow rough Diamond

(108ct weight)

A large rough Diamond

Heart shape cut Diamond

HOW DIAMONDS ARE FORMED

Diamond is formed at great depth in the earth, between 150 and 300 km below the surface and at great temperatures and pressures. By a kind of volcanic eruption the diamonds were pushed up through volcanic pipes of diamond bearing rock such as kimberlite. With gradual erosion kimberlite chimneys were exposed at the earths surface.

RARE DIAMONDS

CENTENARY Diamond - 273.85ct D-colour flawless
The world's largest D-colour flawless diamond, taking 3 years to facet in the late '80s. Gabi Tolkowsky removed 50 carats by hand into 500 carats initally so as not to heat or vibrate the diamond (which might have destroyed it). The result is 247 facets of pure beauty (shaped like the turban of a maharajah), of which there are 3 replicas allowed by the eventual owner. 2 are in museums, and 1 is always in Gabi's pocket. Interestingly, Gabi's hair turned entirely white during the 3 years it took to polish this diamond.

Gabi and Lydia Tolkowsky in Singapore in June 08.

The Pink Sunrise - 29.79ct
This diamond was named when Gabi was flying over China and awoke to the morning sunlight in the airplane, and he saw the pink colour of the sky, which coincided with the colour of this diamond. Hence, he named it the Pink Sunrise, the 6th largest fancy pink diamond in the world. This diamond pays homage to the CENTENARY in its facetting pattern.

The ORANGE TREE - 3.30 ct
This highly unusual diamond was spotted by Gabi, and he peered into the rough diamond and discovered that this diamond had a banding of orange colour in the outside of the diamond and a "core" of white diamond inside. He then minimally facetted the diamond into the shape of an "Orange Tree". This diamond is unique in the world, and cannot be replicated.

GOLDEN JUBILEE - 545.67ct
This diamond, initially mined at 755 carats was considered the "Ugly Duckling" and was used as a test subject for Gabi to experiment on new materials and techniques with which to polish the CENTENARY. Surprisingly, the final 545.67ct diamond became the largest polished diamond in a fire-rose cushion cut. The diamond was purchased by a group of Thai businessmen, and presented to King Bhumibol during his 50th anniversary of his reign - hence the name Golden Jubilee.

Kite Diamond - 17.65ct fancy reddish brown
This unusual diamond is a piece of history, having been used as a test case for Gabi to test his new materials, polishing tools and techniques before being applied on the CENTENARY (which is valued at US$100 million). Had he broken the CENTENARY, he said, he would have been the most famous diamond cutter of all time... NOT.

Inner Secrets Of Gemstones

GEMSTONES

1- What is GEM
2- What are the inner secrets of gemstones?
3- How are gem material formed?

GEM

When we see beautiful GEM the first question is "is it real" and "is it valuable"?

Gem material are those used for adornment or decoration.

And have particular attributes or value acceptability.

ATTRIBUTES OF GEMSTONE

Beauty
Durability
Rarity

GEM MATERIAL FORMED

Gem material are made up from countless atom. In most gems these atoms are orderly, regularly in repeating arrangements. Gemstones formed by geological process inside the earth or its surface. Earth is a store of chemical elements combined in different ways. These combination are constantly being changed by earth processes. Earth crust consists of ridges interlocking plates which move relative to one another. Oceanic plates descend into the mantel at destructive plate margins. Molten rock rises through the crust. Rocks are changed by heat and pressure. Materials weathered from mountains are washed into the sea. Rock, Minerals and Gems are formed and transformed amid the earth's ceaseless activities

Traditionally, gemstones were classified into precious stones and semi-precious stones. Only four types of gemstones were considered precious. They were:

1-Diamond

2-Ruby

3-Sapphire

4-Emerald

Nowadays, all gems are considered "precious," although the four original "cardinal gems" are usually - but not always - the most expensive. There are over 130 species of minerals that have been cut into gems with 50 species in common use. These include:

• Agate
• Alexandrite and other varieties of chrysoberyl
• Amethyst
• Aquamarine and other varieties of beryl
• Chrysoprase
• Chrysocolla
• Feldspar (moon stone)
• Garnet
• Hematite
• Jade-Jadeite and Nephrite
• Jasper
• Lapiz Lazuli
• Malachite
• Obsidian
• Olivine (peridot)
• Opal
• Pyrite
• Quartz
• Spinel
• Tanzanite and other varieties zoisite
• Topaz
• Turquoise
• Tourmaline
• Zircon

Artificial materials used as gems include:

• High-lead Glass
• Synthetic cubic zirconia
• Synthetic corundum
• Synthetic spinel
• Synthetic moissanite

There are a number of organic materials used as gems, including:

• Amber
• Bone
• Coral
• Ivory
• Jet
• Mother of pearl
• Pearl
• Tortoiseshell