Monday, June 28, 2010

The 4 C's of Diamonds

The 4 C's are four variables that are used to calculate the value of a diamond -- Clarity, Color, Cut, and Carat Weight.

Clarity describes the clearness or purity of a diamond. This is determined by the number, size, nature, and location of the internal (inclusions) and external (blemishes) imperfections.

The clarity scale is broken down into the following grades:






Free from all inclusions or blemishes.


Internally Flawless

No inclusions visible at 10x magnification.


Very Very Slightly Included #1

Inclusions that are extremely difficult to locate at 10x.


Very Very Slightly Included #2

Inclusions that are very difficult to locate at 10x.


Very Slightly Included #1

Minor inclusions that are difficult to locate at 10x.


Very Slightly Included #2

Minor inclusions that are somewhat difficult to locate at 10x.


Slightly Included #1

Noticeable inclusions that are easy to locate at 10x.


Slightly Included #2

Noticeable inclusion that are very easy to locate at 10x.


Included #1

Obvious inclusions. Somewhat easy to locate with the unaided eye.


Included #2

Obvious inclusions. Easy to locate with the unaided eye.


Included #3

Obvious inclusions. Very easy to locate with the unaided eye.

The above clarity grading scheme is in accordance with the GIA (Gemological Institute of America). It is important to note that the GIA Grading system is not static, and has changed slowly over time.
Be aware! Two methods used to enhance the clarity grade given to a diamond are laser drilling and fracture filling. Laser drilling is the process in which a laser is used to drill a tiny hole into a diamond and the black of the imperfection is then removed. The second treatment is fracture filling. This method is not permanent and therefore not recommended. All clarity treated diamonds must be disclosed as such prior to sale. The Diamond Source USA does not deal with diamonds that have been clarity treated in any way.

Color describes the amount of color the diamond contains. This can range from colorless to yellow with slight tints of yellow, gray or brown. Colors can also range from intense yellow to brown, blue, green, pink and red. These fancy colors are rare and therefore more valuable.






Near Colorless


Faint Yellow


Very Light Yellow


Light Yellow

Be aware! It is possible to influence the color by irradiation treatment followed by heat treatment. This method is not recommended for two reasons. The first is the risk involved with exposure to irradiated objects. The second is the risk of color change over time. All color treated diamonds must be disclosed as such prior to sale. The Diamond Source USA does not deal in diamonds that have been enhanced in any way.

The color of the stone can be determined by using a GIA (Gemological Institute of America) Certified set of master stones and/or the Colorimeter, a computer which accurately grades the color of a polished diamond.

Cut refers to the proportions, finish, symmetry, and polish of the diamond. These factors determine the fire and brilliance of a diamond. Well cut diamonds sell at a premium and poorly cut diamonds sell at discounted prices. With the advent of technology, the cut of the diamond can be determined through the use of the Dia-Mension system, a computerized system which takes accurate measurements and proportions of a diamond in seconds, in addition to the standard millimeter gauge.

As an example, a round brilliant cut, which has 58 facets, is shown below. Since the quality of the cut is directly responsible for the stone's beauty, the precision with which the facets are arranged is of prime importance. They determine the amount of light reflected to the eye, called brilliance.

The proportions displayed by the stone are very significant. Two of the key factors in the grading of cut quality -- table percentage and depth percentage -- are usually expressed on grading reports. Measurement of three different parameters allows for easy calculation of these percentages by using the formulas expressed below.

For example, for a round brilliant cut diamond, table percentage is calculated as follows:

Table (%) = longest table measurement (in mm)
average girdle diameter (in mm)

And for depth percentage:

Depth (%) = depth (in mm)
average girdle diameter (in mm)

Without attention to quality cutting, light is lost and not returned to the eye.

Proportions Criteria are as shown below:

"Premium Cut"

"Tolkowsky Ideal Cut"

"Excellent Ideal Cut"

Total Depth

58.8% - 63.8%

58.0% - 63.8%

59.2% - 62.4%

Table Size

58.0 - 61.0%

53.0% - 58.0%

52.5% - 58.4%

Crown Height

13.0% - 17.0%

14.2% - 16.2%


Crown Angle

32.7° - 36.3°

33.7° - 35.8°

32.5° - 35.4°

Pavilion Depth

41.7% - 45.0%

42.2% - 43.8%

41.5% - 44.4%

Each cut style above represents, in the opinion of its respective designer, those proportions which best balance the qualities of brilliance and dispersion ("fire") within a round diamond.

Carat is the unit of weight for the diamond. A carat is further subdivided in 100 points (0.01 carat = l point). One carat is equal to 0.20 grams. Value per carat increases with carat size, because larger rough diamonds occur less frequently. In other words, 2 half-carat diamonds taken together will not cost as much as 1 one-carat diamond, as the one-carat stone is rarer.

Diamonds can be cut in various shapes....

Shape: Round Brillant

Shape: Oval

Shape: Marquise

Shape: Pear

Shape: Heart

Shape: Emerald

Shape: Princess

Learn how to buy a gemstone in 7 simple steps.

Diamond Grading Guide: How to Buy a Diamond, Learn the 4Cs of diamond value by Gemological Institute of America

Tuesday, June 15, 2010

The UD range of pendent......

UDP 691
Diamonds: 1.14ct

UDP 647
Sapphire: 0.39ct
Diamonds: 0.45ct

UDP 645
Diamonds: 2.72ct

UDP 643
Diamonds: 0.97ct

UDP 641
Diamonds: 0.51ct

UDP 690
Diamonds: 0.62ct

UDP 646
Diamonds: 0.42ct

UDP 642
Diamonds: 0.73ct

UDP 639
Diamonds: 1.41ct

The UD range of rings.....

UDR 719
Diamonds: 1.37ct

UDR 717
Diamonds: 0.60ct

UDR 711
Diamonds: 1.24ct

UDR 708
Diamonds: 1.10ct

UDR 706
Daimonds: 1.39ct

UDR 704
Diamonds: 1.86ct

UDR 699
Diamonds: 0.74ct

UDR 688
Diamonds: 1.00ct

UDR 686
Diamonds: 0.90ct

UDR 684
Diamonds: 0.91ct

UDR 675
Diamonds: 0.50ct

UDR 672
Diamonds: 0.92ct

UDR 670
Diamonds: 0.78ct

UDR 668
Diamonds: 2.78ct

UDR 654
Diamonds: 1.65ct

UDR 652
Diamonds: 0.92ct

UDR 670
Diamonds: 1.20ct

UDR 718
Diamonds: 1.18ct

UDR 716
Diamonds: 1.08ct

UDR 714
Diamonds: 0.94ct

UDR 712
Diamonds: 2.42ct

UDR 709
Diamonds: 1.24ct

UDR 707
Diamonds: 0.46ct

UDR 705
Diamonds: 1.30ct

UDR 703
Diamonds: 0.81ct

UDR 700
Diamonds: 0.76ct

UDR 698
Diamonds: 2.73ct

UDR 687
Diamonds: 1.36ct

UDR 685
Diamonds: 1.03ct

UDR 671
Diamonds: 1.02ct

UDR 669
Diamonds: 0.78ct

UDR 655
Diamonds: 0.57ct

UDR 653
Diamonds: 2.43ct

UDR 651
Diamonds: 0.66ct

UDR 649
Diamonds: 1.20ct