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Untreated Gemstones-Untreated Emerald
 
Weight : 0.73ct
Size(mm) : L5.9 x W4.6 x D3.22
Zambia, Untreated
Gem Quality

In many cases, some imperfection will be visible in emerald. It is impossible for a cutter to avoid all of them when polishing a stone. Therefore, throughout history, oils have been used to mask flaws in emerald. If lasting beauty is what we seek, then untreated emerald is our only choice.
A major source of small, untreated emeralds is the Sandawana mine in Zimbabwe.


Untreated stones of 0.5 ct can be found in Zambia. There are few untreated emeralds from Columbia and other areas.

Setting an emerald in yellow gold imparts yellow to the green color, further bringing out its beauty. The use of yellow gold is especially indispensable for the strongly bluish color of Zambian emeralds.
 
Map of Major Sources
Emerald
 
Fracture-Filling of Emerald
Oils and polymers are used to fill fractures, resulting in a more beautiful, darker color. However, over time, the oil may disintegrate or the polymers degrade, leading to a loss in beauty.
Moderate oil treatment
Heavy oil treatment
Technical advances in controlling pressure, started in the I970s, have led to oil and polymer treatment becoming much more effective. This in turn has resulted in a huge increase in the number of treated stones on the market: an increase supported by demand. However, the value of these stones is low, so caution is necessary.
Note: Even an untreated stone sometimes reveals traces of oil under analysis. This is because during the examination of the rough material and polishing, oil and water are used to protect the stone. While every effort is made to remove any remaining oil, sometimes traces remains. These are insignificant and will not affect the quality of the stone.
Characteristic inclusions according to country of orlgin
The particular environment present during the crystallization process of each gemstone, hundreds of millions of years ago, accounts for each one's unique character.
Sandawana mine
Typical needle-like tremolite inclusions are seen here crisscrossing each other.
Zambian mine
Liquid and air inclusions trapped during crystallization.
 
 
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