Why diamonds are expensive?
Rough Diamond
Rough diamond is very rare.
By average 250 tons of mined ore can produce 1ct of unpolished diamond
1ct = 0.2gram, 250 ton = 50 million grams
Hardness of Diamond ranked 1st in Mohs Scale (a relative scale)
Moissanite reads 9.25 and Corundum reads 9
Value of a Diamond
Extremely Rare
Hardest material on earth
Ability to refract and reflect light
If we have not noticed, no one is using a gem quality diamond to cut glasses.
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| Note: Scale between 9 and 10: but diamond (10) is four times as hard as (9) corundum |
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钻石的价值由何而来
钻石原石
1．地球上极为罕有
钻石原石是非常罕有的。
平均250吨被开采的矿石可以产生1克拉未打磨的钻石原石
1克拉 = 0.2克， 250吨= 5千万克
2．钻石的硬度在摩氏标度中排列了第1 (注意：摩氏标度是一个相对尺度)
莫桑石 SiC =9.25，
刚玉 = 9
(9 和10在日在摩氏标度的绝对硬度是400 比1500)
3．折射和反射光的能力 （其它宝石没能与之相比）
我们注意到的是，没人使用宝石质量钻石来雕刻玻璃。
钻石切割:是指钻石高度与直径的比值，钻石台面宽度与直径的比值。 不要和钻石状形所混淆。 圆的钻石有最高的能力折射和反射光。 是可能增加钻石的光芒光彩重要因素。
什么是理想切割的钻石？
让我们比较 石英 和 钻石 之间的反射和折射光
注意到 那些细微光线通过 组体的光角度的差别吗 ？
理想的切割将最大限度地利用光的反射，从而产生了辉煌的移动和静止的最佳平衡光, 钻石切割太 浅 或太厚 可能导致 鱼眼 或 钉头 效应
这就解释了为什么一个理想切割的石英有时似乎比切割欠佳的钻石辉煌. 基于上述认识，你会花费3000美元买切割欠佳的钻石？或买一个理想切割的石英30美元看起来更漂亮？
以下的是石英或钻石？是好是坏？
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Diamond Cuts
Refer to the arrangement of a diamond's facet. Not to confused with diamond's shape. Round Brilliant diamond has the highest ability to refract and reflect light. The ONLY factor which could increase the brilliance of a diamond.
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| The Bad, The Ugly or the Good? |
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| Ideal Cut Diamond with Excellent Symmetry |
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What is Ideal Cut Diamond
Let us compare the reflection and refraction between Quartz and Diamond difference, note the tiny difference in the optical angle the light pass through the mass.
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Ideal Cut will maximize the brilliance from light reflection thus produce the optimal balance of MOVING and STATIC light
With the above understanding, would you spend US$3000 for a poorly cut diamond which looks worst than a US$30 ideal cut quartz?
A diamond cutting too shallow or too thick might result in fish eye or nail head effect
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| Thick girdle gives extra weight |
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Little knowledge is dangerous, thus the idea of INFORMED CHOICE
Diamond Prices
Diamonds are cut by human being. Diamond price are based on factors including but not limiting to the following factors:
1. DTC rough diamond selling price to the sight holders
2. World economy, demand and supply
3. Rough diamond price outside the DTC and big players selling price
4. Inventory level of the diamond manufacturers
5. Financial strength of the diamond dealers
6. Financial strength of the diamond retailers
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Sizes vs Value of a diamond
Giving the Color, Clarity and Cut being equal, the bigger the diamond would fetch a higher value. This is more evident in the border line size of a diamond.
Eg .99ct DIF vs 1.00 DIF
1% different in size
80% difference in Value (1 to 1.8)
Thus weight saving is a common practice for the diamond manufacturers
Brilliance vs Weight Saving
Unfortunately, weight saving relate directly to the Brilliance (Proportion and symmetry) of a diamond. Many of the so called MISTAKE of a diamond other than the size, color and clarity was made on purpose to save weight. Many of the retailers are reluctant to disclose the information to the customers especially when certain feature of the diamond report was marked as very good or excellent
Round vs Fancy shape Diamond
Ask yourself a question, what shape you usually see for a big diamond exposed in the media for auction. Get the picture? If not, come and talk to us
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| The birth of a happy Pug--go to last page .... |
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常见的误解
八心八箭 vs. 完美车工
完美车工
光辉闪耀 Brilliance ，重量节省 Weight Saving ，和 理想切工 ideal cut 有密切相关. 他们包括了 1. 技术工人，2. 高技术，3. 牺牲重量而获得最大的辉煌
理想切割公式 Ideal Cur Formula 是一个对钻石辉煌的较大贡献者
左图显示了理想切割公式
台面 53-58%
冠部 14.5-16.2%
亭部 42.4-43.5%
腰部 薄 –略厚
底尖 没有，非常小
例如2 克拉钻石原石.
钻石切割厂可以选择以
理想的公式，生产出一个最光辉闪耀的钻石。 85克拉EXEXEX，
或为了最大限度地提高重量，他可以生产出1克拉VGVGG一个不漂亮的钻石
(左图) 粗腰部会减少的钻石辉煌,但可以增加多达10％的重量
八心八箭另一方面，主要涉及钻石的对称性。如果对称 symmetry 性评为优秀 excellent ，可能90％已上可以看出有八心八箭的效果
八心八箭效果与钻石的比例联想较少，因此贡献钻石的光辉不大. 完美的对称是对已经完美切割钻石一个加分的因素. 记住，不理想的切割钻石（non ideal cut太厚或太薄但有完美对称），也可能有八心八箭的效果. 只可惜八心八箭不会影响钻石的光辉或亮度的效果
对于以价格来言，理想切割钻石ideal cut (带或不带八心八箭效应都可以) 比八心八箭（H&A non ideal cut非理想切工）钻石是昂贵得多，
下图显示了不良八心八箭钻石，没有光辉闪耀
右图显示了 锯 或 没锯的钻石大 vs 小台面
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The History and Prices system
DTC Diamond Trading Company (also known as DeBeers 40%), Rio Tinto(20%), and Alrosa 20-25%) collectively controlled more than 80% of the rough diamond business. Price of the rough diamond was placed on each assortment based on different quality of the diamonds. DTC is the leader in fixing the price? Rio Tinto and Alrosa normally follow the suit when it comes to price adjustment.
DTC and Rio Tinto is using the sight holder system where they selectively invite diamond cutters which meet their high standard with regards to financial strength, business ethic, marketing capability etc in order to enter the CLUB to make direct purchase through the sightholdership[1].
With the decision Supply of Choice being implemented 6 years ago, DTC has successfully increased the efficiency in marketing the diamond and its related product worldwide, they eliminated more than 50% of their sightholdership from over 200 to about 70, increased the presence of diamond marketing program around the globe and increased their stock price at a very handsome rate. However, as the very elite sightholders in the world[2], members normally were NEVER allowed to reject anything which was agreed and distributed by DTC on bi-monthly sight in London.
Below is an example on how the action of DTC helped to stabilize the diamond price of the last 2 years.
In the beginning of 2009, rough diamond price has fallen to its lowest level, polished wholesale diamond price tumbled between Feb and March 2009[3]. DTC act quickly to reduce its sight amount and stabilized the rough price.
In April of 2009, wholesale diamond price stabilized and increased about 5%. The increase was not related to market economy or retail sentiments, but merely because DTC has agreed to cut back for the goods sold to the sightholders.
The price drop for high end diamond eg 2ct-10ct eg DIF EXEXEX outperformed the lower end smaller size diamond due to its limited supply. Some of the larger firm has stopped selling of such goods in order to reserve the asset value.
[1] The direct benefit includes the lower price of the rough and the assurance of the type of diamond received from the sight.
[2] Only 2 Chinese companies qualified as sightholder in 2009
[3] Price reduction in retail was not as obvious as the wholesale market
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| They control over 80% of rough diamond |
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| Typical Brown Rough diamond |
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| Most of the rough diamond are yellowish in color |
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White vs Fancy Color diamond
Anything related to pure RED is extremely rare, you can count the stones found per year all around the world by your fingers. Pink and intense green comes next. However, due to the nature of green formation in a diamond, it is difficult to proof whether the green is naturally radiated. Cheapest of all are the black and brown diamonds. Natural Black diamond actually a b it more than natural brown diamonds. Price of fancy color diamond is NOT as transparent as the white diamond, much more factors complicated the selling price of color diamonds
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| Fancy Yellow Diamond |
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Common misunderstanding
Hearts & Arrows vs Ideal Cut
Brilliance, weight saving and ideal cut are closely related. Their counter part includes Skilled workers, improved technology, sacrificing yield to obtain maximum brilliance.
Ideal Cut
Brilliance, weight saving and ideal cut are closely related. Their counter part includes skilled workers, improved technology, and sacrificing yield to obtain maximum brilliance.
Ideal Cut formula is the MAJOR contributor to the brilliance factor of a diamond.
1?Diamond Table 53-58%
2?Diamond Crown Angle (crown height 14.5%-16.2%)
3?Diamond Pavilion Angle (pavilion height 42.2%-43.5%)
4?Diamond Girdle thickness (Thin-slightly thick)
5?Diamond Culet (pointed)
Diamond cutter can choose to follow the ideal cut formula in order to produce the most brilliant diamond from a rough diamond eg 2carat to say .85 carat EXEXEX, or in order to maximize the weight, he can produce a not so beautiful diamond at 1 carat VGVGG
Hearts and Arrows
On the other hand relate mostly to the symmetry of a stones. If the symmetry is rated as excellent, it is 90% likely that the Hearts and Arrows effect can be seen
Hearts and Arrows effect has much less association to the proportion of a diamond, therefore contributed very little in the brilliance of a diamond. Perfect symmetry is a PLUS factor to the already ideal cut diamond. Remember, non ideal cut diamond (too thick or too thin) with perfect symmetry can also have H&A effect. Unfortunately only the H&A does NOT have any effect in the beauty or brilliance of a diamond.
With regards to price, ideal cut diamond (with or without hearts and arrows effect) is much more expensive than the hearts and arrows diamond.
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Diamond for Commercial Use
Because of the extreme hardness of diamonds, they are often used as an abrasive, and on cutting tools. Diamond particles are embedded in a saw blade, or drill bit to fortify the strength of the blade or bit, and make it cut cleanly for precision work. Diamond blades also come in handy when cutting through extremely hard surfaces like marble or granite. Diamonds are able to withstand higher levels of heat than other blade substances--five times as much as copper. Use of diamonds in mechanical tools reduces friction, and extends the life of the equipment, but it increases the initial cost.
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| What is the object in view? |
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| You guessed it--some very macro diamond in a blade |
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In ancient Greece it was believed that diamonds were pieces of stars that had fallen to earth. It was said by some that they were the tears of the gods. Another legend tells of an inaccessible valley carpeted with diamonds that were patrolled by birds of prey and guarded by snakes....
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