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12.45 CTS ALEXANDRITE - SPECIMEN FROM TANZANIA [S-SAFE249]
- 存貨單位
- 尺寸(毫米)
- 10.000 x 7.000 x 6.000mm
- 重量 (cts)
- 12.450
- 類型
- Specimen
- 顏色
-
ALEXANDRITE SPECIMEN
This is a natural untreated Alexandrite specimen from Tanzania which i bought from the miner on my last trip there. They are not suitable for faceting but can be cabbed or kept as a specimen.
The most sensational feature about this stone, however, is its surprising ability to change its colour. Green or bluish-green in daylight, alexandrite turns a soft shade of red, purplish-red or raspberry red in incandescent light. This unique optical characteristic makes it one of the most valuable gemstones of all, especially in fine qualities.
Alexandrite is very scarce: this is due to its chemical composition. It is basically a chrysoberyl, a mineral consisting of colourless or yellow transparent chrysoberyl, chrysoberyl cat’s eye and colour-changing alexandrite (also in cat’s eye varieties). It differs from other chrysoberyls in that it not only contains iron and titanium, but also chromium as a major impurity. And it is this very element which accounts for the spectacular colour change. Rarely, vanadium may also play a part. According to CIBJO nomenclature, only chrysoberyls displaying a distinct change of colour may be termed alexandrite.
Like many other gemstones, alexandrite emerged millions of years ago in a metamorphic environment. But unlike many others, its formation required specific geological conditions. The chemical elements beryllium (a major constituent in chrysoberyl) and chromium (the colouring agent in alexandrite) have contrasting chemical characteristics and do not as a rule occur together, usually being found in contrasting rock types. Not only has Nature brought these contrasting rock types into contact with each other, but a lack of the chemical element silica (the second most common element in the Earth’s crust) is also required to prevent the growth of emerald. This geological scenario has occurred only rarely in the Earth’s history and, as a result, alexandrite crystals are very scarce indeed.
- 存貨單位
- 尺寸(毫米)
- 10.000 x 7.000 x 6.000 mm
- 重量 (cts)
- 12.450
- 類型
- Specimen
- 顏色
-
ALEXANDRITE SPECIMEN
This is a natural untreated Alexandrite specimen from Tanzania which i bought from the miner on my last trip there. They are not suitable for faceting but can be cabbed or kept as a specimen.
The most sensational feature about this stone, however, is its surprising ability to change its colour. Green or bluish-green in daylight, alexandrite turns a soft shade of red, purplish-red or raspberry red in incandescent light. This unique optical characteristic makes it one of the most valuable gemstones of all, especially in fine qualities.
Alexandrite is very scarce: this is due to its chemical composition. It is basically a chrysoberyl, a mineral consisting of colourless or yellow transparent chrysoberyl, chrysoberyl cat’s eye and colour-changing alexandrite (also in cat’s eye varieties). It differs from other chrysoberyls in that it not only contains iron and titanium, but also chromium as a major impurity. And it is this very element which accounts for the spectacular colour change. Rarely, vanadium may also play a part. According to CIBJO nomenclature, only chrysoberyls displaying a distinct change of colour may be termed alexandrite.
Like many other gemstones, alexandrite emerged millions of years ago in a metamorphic environment. But unlike many others, its formation required specific geological conditions. The chemical elements beryllium (a major constituent in chrysoberyl) and chromium (the colouring agent in alexandrite) have contrasting chemical characteristics and do not as a rule occur together, usually being found in contrasting rock types. Not only has Nature brought these contrasting rock types into contact with each other, but a lack of the chemical element silica (the second most common element in the Earth’s crust) is also required to prevent the growth of emerald. This geological scenario has occurred only rarely in the Earth’s history and, as a result, alexandrite crystals are very scarce indeed.
運輸商 | 運送至:國家 | 運送到世界其他地區 |
---|---|---|
FedEx | $12.00 / :幾天天 | $39.00 / :幾天天 |
:國家
FedEx 對包含 2 或更多商品的訂單折扣為 $12.00
世界其他地區
FedEx 對包含 2 或更多商品的訂單折扣為 $39.00
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Registered Shipping | $9.00 / :幾天天 | $16.00 / :幾天天 |
:國家
Registered Shipping 對包含 2 或更多商品的訂單折扣為 $9.00
世界其他地區
Registered Shipping 對包含 2 或更多商品的訂單折扣為 $16.00
|
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積極的
Beautiful agate piece , and as always fast efficient service from Sedagems
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積極的
Gorgeous stones, very happy
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積極的
Gorgeous stone, very happy
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。