鑽石知識 - CLARITY(淨度)

Gia一定分grade分到好細，而且主要係建基於10倍放大後既效果，又係o個句「邊個會拎隻放大鏡黎睇你粒石」，下面係77diamonds.com對於每個grade可唔可以用肉眼睇到既分享。

http://www.77diamonds.com/compare-diamond-certificates.html

SI1最值得揀，有數既可以升多級揀VS2(預多5千至1萬)，冇數既就揀SI2(記得叫人地幫你CHECK清楚係米真係EYE CLEAN)。

	GIA
100% 10x loupe clean	FL/IF
100% 10x loupe clean	VVS1
100% 10x loupe clean	VVS2
100% eye clean (50% 10x loupe clean)	VS1
100% eye clean	VS2
80% chance eye clean	SI1
10% chance eye clean	SI2
Not eye clean	I1
Not eye clean	I2

GIA

Because diamonds formed deep within the earth, under extreme heat and pressure, they often contain unique birthmarks, either internal (inclusions) or external (blemishes).

Diamond clarity refers to the absence of these inclusions and blemishes. Diamonds without these birthmarks are rare, and rarity affects a diamond’s value. Using the GIA International Diamond Grading System™, diamonds are assigned a clarity grade that ranges from flawless (FL) to diamonds with obvious  inclusions (I3).

Every diamond is unique. None is absolutely perfect under 10× magnification, though some come close. Known as Flawless diamonds, these are exceptionally rare. Most jewelers have never even seen one.

The GIA Clarity Scale contains 11 grades, with most diamonds falling into the VS (very slightly included) or SI (slightly included) categories. In determining a clarity grade, the GIA system considers the size, nature, position, color or relief, and quantity of clarity characteristics visible under 10× magnification.

Flawless (FL) - No inclusions or blemishes are visible to a skilled grader using 10× magnification
Internally Flawless (IF) - No inclusions and only blemishes are visible to a skilled grader using 10× magnification
Very, Very Slightly Included (VVS1 and VVS2) - Inclusions are difficult for a skilled grader to see under 10× magnification
Very Slightly Included (VS1 and VS2) - Inclusions are clearly visible under 10× magnification but can be characterized as minor
Slightly Included (SI1 and SI2) - Inclusions are noticeable to a skilled grader using 10× magnification
Included (I1, I2, and I3) - Inclusions are obvious under 10× magnification and may affect transparency and brilliance

How did the GIA Clarity Scale come about?

Like the color scale, GIA’s clarity grading system developed because jewelers were using terms that were easily misinterpreted, such as "loupe clean," or "piqué." Today, even if you buy a diamond in another part of the world, the jeweler will likely use terms such as VVS1 or SI2, even if her language is French or Japanese instead of English.

http://www.gia.edu/lab-reports-services/about-the-4cs/index.html

BLUE NILE

鑽石的淨度有很多描述，但就鑽石 4C 而言，淨度最容易理解，而且根據很多專家所言，淨度通常對鑽石的外觀的影響最小。 淨度其實是指除了最優質的鑽石以外，出現在所有鑽石的細小﹑天然瑕疵。 珠寶鑑定家用一系列不同的技術名稱描述這些瑕疵，包括污點及包裹體及其他名稱。 瑕疵數量最少及最小的鑽石的淨度分級最高。 因為這些瑕疵往往十分微小，一般不會在任何可察覺的情況下影響鑽石的美麗。

FL, IF - 完美無瑕﹑內部完美無瑕： 沒有內部或外部瑕疵。 內部無瑕： 沒有內部瑕疵。 非常罕有。

VVS1,VVS2 - 極輕微瑕： 放大10 倍之下非常難見瑕疵。 品質優異的鑽石。

VS1,VS2 - 輕微瑕： 瑕疵通常在肉眼下看不見。 比 VVS1 或 VVS2 分級便宜。

SI1,SI2  - 微瑕： 放大 10 倍可見瑕疵，在肉眼下亦可能看見。 良好鑽石價值。

I1, I2, I3 - 瑕疵： Blue Nile 並不提供 I 級淨度的鑽石。

甚麼淨度分級適合我？

·                 選擇「肉眼無瑕疵」鑽石，則肉眼下沒有任何可見瑕疵的鑽石。 這種淨度的鑽石具備優秀的價值，比完美無瑕 (FL) 或內無瑕 (IF) 鑽石便宜得多，後兩種鑽石極為罕有，價格非常昂貴。

·                 分級為微瑕 (SI) 的鑽石的瑕疵在肉眼下經常都不能察覺得到，因而具備極好的價值。 如果您考慮購買 SI 淨度分級的鑽石，請致電鑽飾珠寶顧問，顧問會審核鑽石，確保在肉眼下看不見瑕疵。

http://zh-hk.bluenile.com/diamonds/diamond-clarity

周大福

淨度是指鑽石的「純潔」程度。由於鑽石乃天然礦物，因此可能會有內含物、裂縫或其他未晶化碳物等，而這些天然特徵會影響光線透過鑽石，影響鑽石的外觀。因此，鑽石的內含物愈少，即淨度愈高，光芒折射也愈多，鑽石便愈璀璨，價值自然也會愈高。

一般而言，在顏色級別、重量相同的情況下，鑽石淨度愈高，價值也會愈高。

G..I.A淨度評級：

u        FL極罕有，在10倍放大鏡下，檢視不到鑽石內、外的瑕疵，可稱完美無瑕

u        IF罕有，內部完美無瑕，表面稍有微疵

u        VVS1, VVS2極微量內含物，微量視覺分別

u        VS1, VS2含極小瑕疵，不易看到

u        SI1, SI2含小瑕疵，肉眼容易看到

u        I1, I2, I3含有較明顯瑕疵，肉眼可見。

http://www.chowtaifook.com/index.asp#hk,b5,knowledge

六福

淨度可分為「表面瑕疵」和「內部瑕疵」。由於鑽石是天然礦物，在形成時會包含了其他的天然物質或裂縫在內，這些內含物會阻礙光線透過鑽石，影響鑽石的外觀。淨度評級是以10倍放大標準器，檢視鑽石的表面瑕疵及內含物的大小、形狀、顏色、數量及位置，淨度愈高，價值愈珍貴。淨度評級可分為以下六級: FL / IF (完美無瑕)
VVS1/VVS2 (極輕微瑕級)
VS1/VS2 (輕微瑕級)
SI1/SI2 (微瑕級)
I1/I2/I3 (有瑕疵)

每顆鑽石的內含物均獨一無二，而這些內含物正正就是每顆鑽石的獨特之處。

http://www.lukfook.com.hk/prodmain_diamond.asp