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Learn About Diamonds with Center Stone Education

Dafina Jewelry Center Stone Guide
Center Stone Education

Diamond

The precise value of a diamond is not determined by "4 C's" only, but by at least 10 different important variables:

Carat

Carat indicates the weight of the diamond. 1 carat equals 0.2 grams. Therefor the more mass a diamond gets, the higher carat it is going to have. Heavier/ bigger diamonds are more valuable than smaller ones, only if their other characteristics are all in the same level.

Color

Diamonds are found in different colors in nature ranging from brown to green and pink. However in white diamonds, color refers to the degree of whiteness they have.

White diamonds range from absolutely colorless to pale yellow.

Different tones of color exist because of specific conditions in which diamonds are formed under the earth’s surface. The color grading of white diamonds starts with letter D in alphabetical order and continues down to letter Z.

Diamonds with grades D, E, F are considered colorless (most expensive/ rare), while grades G, H, are considered near colorless (grade G is closest grade to colorless). The tone of yellow starts to be noticeable from grade I, and at grade J and below, the diamond is considered pale yellow.

Clarity

Clarity refers to the degree of inclusions or impurities that are visible in or on a diamond.

Inclusions could be the result of presence of foreign microscopic materials that are trapped in the diamond when it was forming, or structural imperfections such as cracks, chips, or shades/ clouds.

Most demanded diamonds are the ones with the least inclusions.

Gemologists categorize diamonds into 5 main groupings in regards to inclusions:

FL/ IF:
Flawless (no inclusions inside or on the surface of diamond)/ Internally Flawless (no inclusions inside the diamond). These diamonds are extremely rare.
VVS1/ VVS2:
Very very slightly included under X10 magnification. Inclusions are not visible to the naked eye.
VS1/ VS2:
Very slightly included under X10 magnification. Inclusions are not visible to the naked eye.
SI1/ SI2:
Slightly included. Inclusions are visible under X10 magnification, and most likely to naked eyes.
I1/ I2/ I3:
Included.

Cut

Cut refers to the proportion and sizes of facets, and alignment of width, length, depth, and diameter of a diamond. The more precisely all these sizes and facets are aligned, the stronger light reflection a diamond will produce, which results in nicer appearance and more brilliance.

When a diamond is cut with correct proportions, it can send back most of the light it receives from the environment and create more sparkles.

Therefore cut is one of the most important characteristics of a diamond, determining its shine, light performance, and appearance.

Gemologists categorize diamonds into 5 groupings in regards to cut:

Excellent or Ideal cut:
With this accuracy of cut, almost all the light that enters the diamond is going to be reflected back as sparkles. Excellent cuts are rather rare.
Very good cut:
Produces almost the same level of sparkle as the excellent cut, at a lower price.
Good cut:
Produces less sparkle than “excellent” and “very good” cuts; however for a much less price.
Fair cut:
Although there are still some sparkles, but the diamond won’t shine as much as a good cut diamond.
Poor cut:
Diamond looses most of the light that enters it due to bad proportions and symmetry. Diamonds that are too deep, or too shallow are considered poor cut diamonds.

Polish

Refers to the finishing of sides, surfaces, and facets of a diamond and shows how clean and smooth they are. Diamonds that are well finished have less lines and scratches visible on their surfaces and more defined and crisp edges where the surfaces meet. 

Polish affects the amount of shine and brilliance each diamond generates, and is graded as: E/ Excellent, VG/ Very good, G/ Good, F/ Fair, P/ Poor.

Symmetry

The overall alignment of a diamond is its symmetry, and shows how similar the right and left sides of it are, when you split the diamond in half by a vertical imaginary line. 

In a symmetrical diamond, the table is exactly centered at the top of the gemstone, table and girdle lines are parallel when viewed from the side, and culet is in the center of the table facet when viewed from the top. Symmetry is graded as: E/ Excellent, VG/ Very good, G/ Good, F/ Fair, P/ Poor.

Depth Percentage

The height of a diamond, measured from the culet to the table is called depth. The depth of a diamond is expressed as a percentage of its average diameter.

As shown in the above picture, too deep or too shallow diamonds distract the perfect light reflections, and lower the volume of sparkles.

Depth % is one of the key parameters that affects the light performance and play of light in a diamond. Proper and complete light reflection in a diamond only occurs within a specific depth percentage. 

Table Percentage

Table is the biggest facet of a symmetrically cut gemstone, which is its top surface. The size of a diamond's table is expressed as a percentage of its average diameter. 

Table % is the other key parameter that affects the light performance and play of light in a diamond. Too big or too small tables fail to properly concentrate all the light reflections and would give the diamond a dull look. 

Culet

Culet is the lowest point of a diamond underneath the pavilion, where all facets meet. In a very well cut diamond, culet is graded as "None" meaning it is so sharp that it’s undetectable by naked eyes. This also indicates that the cut and light performance of the diamond are very precise. Culet (when exists) can distract light reflections and interfere with light performance of a diamond and make it weaker.

Usually diamonds with culet other than "none" are not recommended.  

Florescense

The diamond’s tendency to emit a pale glow when subjected to ultraviolet light is called Florescense. Usually this glow is unnoticed but in some cases this can give the diamond a milky or oily look when viewed from the top. Grades of fluorescence are: None, Faint, Medium, Strong, and Very Strong, with "None" being the most desirable.

  • Each one of these factors can significantly change the quality and price of the diamond, however, a “Dafina One Carat Diamond” is precisely set to satisfy those who seek the highest standards in a one-carat diamond with equal attention to all parameters and factors at the same time.

Sapphire

Sapphires are considered to be one of the hardest gemstones (second after diamond) and are found in almost every color in nature, with pink and blue as the most popular ones.

Although sapphires are mined in many areas in the world, the best quality of sapphires come from Ceylon (Sri Lanka) with extraordinary richness in color and purity.

The value of sapphires is determined based on a variety of factors including: the geographic location in which they are mined, color, color zoning, color richness and intensity, cut, clarity, treatment, and carat.

Origin

Sapphires are mined in many different places in the world including: Africa, Australia, India, Thailand, Sri Lanka, China, and Madagascar.

The best sapphires usually come from Sri Lanka (known as Ceylon Sapphires) and are unique in color, clarity and luster compared to sapphires from other countries.

Color

Sapphires are found in a wide range of colors including: blue, pink, yellow, green, and white. Some colors in sapphires are more rare and therefore more valuable such as a vivid pinkish orange that is called Padparadscha. However regardless of what specific color the sapphire is, there are other attributes of color that influence the value of a sapphire such as: tone and intensity.

Tone

Tone is referred to shades of darkness in one specific color. These shades could be very minimal and make the color very pale at one extreme, or they could be strong and bring the color closer to black at the other extreme.

Color richness

Intensity or richness of color is one of the most important factors in determining the value for a sapphire.

The most valuable sapphires have the most color intensity and saturation, and the least color zoning; therefore the color is vivid and constant throughout the entire gemstone.

For instance the most desirable color in blue sapphires is velvety blue to violetish blue with medium to medium dark tones that is constant throughout the gemstone.

For pink sapphires also a medium to medium dark tone of a vivid pink is most desireable.

Color zoning

Color zoning is areas of different colors in one gemstone, and is a usual characteristic in sapphires. In a blue sapphire crystal usually there are two zones of blue and lighter blue beside each other. Therefore when cutters are shaping a crystal into a facetted sapphire, they intend to exclude those less attractive areas and have the entire gemstone cut from one color zone. The value of a sapphire is even higher when that zone has a premium and vivid color.

Cut

Sapphires unlike diamonds don’t have a standard grading system for their cut.

Each colored gemstone is very unique in regards to its color distribution, intensity, and consistency; therefore the best cut for each gemstone is the one that amplifies its unique brilliance and color/ tone attributes.

Nevertheless, in an excellent cut sapphire, all facets and surfaces must be extremely clean, sharp and aligned. If the gemstone is round, the diameter should be the same in all places with no asymmetry, and the table which is the biggest facet on top of the gemstone, must be exactly centered and symmetrical when view from the top; also the table and girdle lines must be parallel when gemstone is viewed from the side.

When looked from the side, the culet (lowest point of the gemstone underneath the pavilion) must be exactly in the middle with no leaning towards left or right, and the general profile of the gemstone must be symmetrical and proportionate with no bulging.

The girdle line is another area to pay attention to, which should not be too thick or too thin.

Clarity

Clarity refers to the amount of inclusions visible in a sapphire. Because the environment in which sapphires naturally form is usually rich with other elements and minerals, they are often trapped in a sapphire crystal in the form of inclusions. These mineral inclusions are called needles since they mostly form long thin lines.

In general, inclusions lower the value of a sapphire and if they are not visible to naked eyes, the gemstone is considered “eye-clean” which falls into premium quality.

Treatment

Most sapphires are heat treated to improve their color and clarity. Although heat treatment is an accepted industry standard, there are few other treatments that are not considered ethical and are not accepted by the industry. One of these treatments is oil filling in which the sapphire is injected with oil to fill the cracks and imperfections. In this case the oil can be pushed out over time and leave the sapphire with an undesirable color and appearance.

Carat

Carat indicates the weight of the sapphire. 1 carat equals 0.2 grams. Therefor the more mass a sapphire gets, the higher carat it is going to have. Heavier/ bigger sapphires are more valuable than smaller ones, only if their other characteristics are all in the same level.