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BIG NATURAL EMERALD FROM BRASIL 15,62cts
- 存貨單位
- 尺寸(毫米)
- x x mm
- 重量 (cts)
- Certified Gemstones
- 不
- Shape
- Emerald
- 類型
- Faceted
- 顏色
-
This is a very big natural emerald from the mines of Brasil...Pear shape...15,62 carats...18,29 x 12,87 x 9,20mm...Opaque and color enhanced...
Emerald Treatments
Natural emerald, more than any other kind of gemstone, tends to be heavily included. Most emeralds have not only numerous internal inclusions and fractures, but also tiny surface breaking fissures or cracks. For this reason, the vast majority of emeralds are treated to improve their clarity. This practice is widely accepted in the trade, but there are is some controversy surrounding recent developments in emerald treatments.
The traditional treatment for emerald is oiling with cedar oil. Cedar oil is a natural product from cedar trees and is colorless, viscous and very sticky. It can be produced in a very pure form and has a number of industrial uses. It is used as an immersion oil in light microscopy; as an ingredient in insect repellents; as an anti-bacterial; and as a food preservative. It is also often used for its aromatic properties, especially in aromatherapy. Cedar oil has been used for fracture-filling emerald because it has a refractive index that is similar to emerald.
Since cedar oil is so viscous and sticky, it is not easy for it to penetrate the microscopic cracks in emerald. So it requires some heat and pressure to do the job. First the emeralds are cleaned, usually in an acid bath. Then the gems are placed in a heated hydraulic cylinder with pure cedar oil and locked tight. The heat liquifies the cedar oil and the pressure helps it penetrate any tiny cracks in the emerald.
After several hours the cylinder is left to cool. The stones are then removed and cleaned. The cedar oil that has penetrated the emerald returns to its thick, viscous state, making it very difficult for it to leak out without the aid of ultrasonic cleaners, excessive heat or harsh solvents.
Traditional oiling is stable but not permanent. Eventually an oiled emerald will require re-oiling to keep it looking at its best. So there have been a number of attempts to introduce new fillers that will be more permanent. These include natural and artificial resins (such as Opticon), and polymers and prepolymers. The use of these new fillers has created some controversy in the market, particuarly in cases when the exact filler has not been disclosed.
One important thing consumers want to know is the degree to which an emerald has been enhanced. This is perhaps even more important than the type of filler used. Some labs, such as the GIA (Gemological Institute of America) have tried to develop classification schemes that classify emerald enhancement as minor, moderate or significant, depending on how many surface-reaching fissures have been filled.
- 存貨單位
- 尺寸(毫米)
- x x mm
- 重量 (cts)
- Certified Gemstones
- 不
- Shape
- Emerald
- 類型
- Faceted
- 顏色
-
This is a very big natural emerald from the mines of Brasil...Pear shape...15,62 carats...18,29 x 12,87 x 9,20mm...Opaque and color enhanced...
Emerald Treatments
Natural emerald, more than any other kind of gemstone, tends to be heavily included. Most emeralds have not only numerous internal inclusions and fractures, but also tiny surface breaking fissures or cracks. For this reason, the vast majority of emeralds are treated to improve their clarity. This practice is widely accepted in the trade, but there are is some controversy surrounding recent developments in emerald treatments.
The traditional treatment for emerald is oiling with cedar oil. Cedar oil is a natural product from cedar trees and is colorless, viscous and very sticky. It can be produced in a very pure form and has a number of industrial uses. It is used as an immersion oil in light microscopy; as an ingredient in insect repellents; as an anti-bacterial; and as a food preservative. It is also often used for its aromatic properties, especially in aromatherapy. Cedar oil has been used for fracture-filling emerald because it has a refractive index that is similar to emerald.
Since cedar oil is so viscous and sticky, it is not easy for it to penetrate the microscopic cracks in emerald. So it requires some heat and pressure to do the job. First the emeralds are cleaned, usually in an acid bath. Then the gems are placed in a heated hydraulic cylinder with pure cedar oil and locked tight. The heat liquifies the cedar oil and the pressure helps it penetrate any tiny cracks in the emerald.
After several hours the cylinder is left to cool. The stones are then removed and cleaned. The cedar oil that has penetrated the emerald returns to its thick, viscous state, making it very difficult for it to leak out without the aid of ultrasonic cleaners, excessive heat or harsh solvents.
Traditional oiling is stable but not permanent. Eventually an oiled emerald will require re-oiling to keep it looking at its best. So there have been a number of attempts to introduce new fillers that will be more permanent. These include natural and artificial resins (such as Opticon), and polymers and prepolymers. The use of these new fillers has created some controversy in the market, particuarly in cases when the exact filler has not been disclosed.
One important thing consumers want to know is the degree to which an emerald has been enhanced. This is perhaps even more important than the type of filler used. Some labs, such as the GIA (Gemological Institute of America) have tried to develop classification schemes that classify emerald enhancement as minor, moderate or significant, depending on how many surface-reaching fissures have been filled.
運輸商 | 運送至:國家 | 運送到世界其他地區 |
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Standard Shipping - Tracked | $8.00 / :幾天天 | $8.00 / :幾天天 |
:國家
Standard Shipping - Tracked 對包含 4 或更多商品的訂單折扣為 $10.00
世界其他地區
Standard Shipping - Tracked 對包含 4 或更多商品的訂單折扣為 $10.00
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Registered Shipping | $8.00 / :幾天天 | $8.00 / :幾天天 |
:國家
Registered Shipping 對包含 4 或更多商品的訂單折扣為 $8.00
世界其他地區
Registered Shipping 對包含 4 或更多商品的訂單折扣為 $8.00
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積極的
AAAservice thanks
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積極的
very nice piece!
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積極的
The magnifier was defective but the company reimbursed all of my costs including shipping so I was happy working with this seller .
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積極的
Paid and shipped - no feedback left after 100 days
為什麼用戶出價高於自己?
出價時,這是用戶願意為產品出價的最高金額。然後,我們的系統將代表該用戶自動出價,逐步提高出價以保持其作為最高出價者的地位,直至達到指定的最高價。
當出現“自動出價”圖標時,表示我們的系統正在根據用戶的最高出價主動為用戶出價。這可能看起來好像用戶出價高於自己,但這只是系統更新出價以反映用戶最高限額的結果。