Diamond Grading Guide

How to buy an engagement ring?

What do all the acronyms/symbols mean, and how do I evaluate my diamond?

An easy way to think about diamond grading is to remember the 4 C's.

1. Cut (eg. princess cut diamonds)

2. Colour (from D to Z or fancy coloured)

3. Clarity (from flawless to various amounts of inclusions)

4. Carat (the weight of a diamond where 1 ct = 0.2 g or 200 mg, and 5 ct = 1 g)

CUT
These days, with lasers, diamonds can be cut into virtually any shape imaginable. The most popular cut is a brilliant round cut. With its 58 facets, (57 if there's no culet), the angles cut are such that it brings out the most brilliance and fire in the diamond by reflecting light entering the diamond off the back facets and back to your eye while dispersing light into it's spectral colours. A poorly cut diamond will appear to have "windowing" where light escapes out the back facets and doesn't come back to the observer's eye. It won't have as much life and sparkle.   Princess cut diamonds also known as a profile cut, are also popular and have more of a square-shaped table. Marquise, pear-shaped, radiant cut, cushion cut, emerald cut, baguette cut, heart shape and more are other cuts you may hear of. A particular cut may be chosen to better disguise inclusions, or to maximize the carat weight of the original rough diamond crystal. Many times, the maximum carat weight is a sacrifice over the best cut for the diamond since diamonds are sold by how much they weigh.

The cut of a stone refers more to its quality, and not so much to its style of cut.   The quality of cutting is often referred to as its make in the industry. Make grading must consider proportions, symmetry, finish details and polish. Cutters are limited by the hardness of diamond, the placement of inclusions, and the size and shape of the original rough diamond crystal. Diamonds can be cut by hand, or in automated facilities.

COLOUR
The colour of a diamond is a very important factor, and can have a tremendous influence on price. Colored diamonds come in all colours of the rainbow naturally, including black. Colored diamonds can also have their colours enhanced, or colourless diamonds can be treated to another colour.   It's kind of like dying a cotton shirt to a desired colour, only diamond is exponentially harder than cotton, so more intense means are required to alter or add colour to a diamond. Like your shirt, it's still "real", only changed to a different colour. One of the ways to make colored diamonds, or to make a diamond MORE colourless, is to use extremely high pressure and high temperature or (HPHT) treatment. A colourless diamond can be changed to green this way for instance. Other ways to add colour are to use irradiation. The irradiation methods used today have no lingering radiation effects and the diamonds are perfectly safe to wear. These are "acceptable" treatments in the industry. Other less desirable treatments that can alter the value of your diamond is to paint it, use different coloured backings, or to "assemble" a diamond with a different colour to enhance it or make it look more colourless.
In the Cape Series of diamonds, the best colourless diamond grading starts with D for best, or most colourless all the way to Z where a diamond can appear black. Cape Series diamonds are colourless, but as you go down the colour scale, they can appear more yellow, or gray or brownish.
Fancy diamonds are naturally occurring colored diamonds. Canary yellow diamonds fall in this category, and are not to be confused with Cape Diamonds that can appear yellow as you move down the colour grading scheme. Naturally occurring Canary yellow diamonds are more valuable. Naturally occurring blue diamonds are very rare like the Hope Diamond, and most are very pale blue in colour.   Pink diamonds are also less available, and more valuable with red diamonds being the most rare and expensive diamond.

CLARITY
Inclusions are a part of most natural diamonds. Very small inclusions don't affect the beauty of a diamond to the naked eye. They have an effect on price, however, flawless diamonds are very hard to find. Inclusions may be uneven cleavage fractures, or small crystals. The dark appearance is due to a disturbance of reflected light to your eye. A good cutter will if possible cut a stone in such a way to minimize an inclusion by having it to the side, or as high up as possible. Standard clarity determination is usually done with a 10x loupe. Larger stones over 1 ct require a binocular microscope with a 10x magnification. No inclusions or external flaws at this magnification is considered to be flawless. Some short form terms you may encounter from best down the scale are as follows.

1. Flawless
2. VVS-1 and VVS-2 (Very very slight inclusion; difficult to see, especially with small stones)
3. VS-1 and VS-2 (Very slight inclusion)
4. SI-1 and SI-2 (small inclusion, not visible to the naked eye)
5. I-1, I-2, and I-3 (included or imperfect, visible to the naked eye)
6. Promotional (low grade quality, highly included)

CARAT
The standard measurement for weighing diamonds and other gems is the carat weight, seen as the symbol ct, or you may see carat total weight written as cttw. (1 ct = 0.2 g or 200 mg)   Or (5 ct = 1 g). One has to multiply the gram weight by 5 to get the number of carats. Diamonds are usually sold based on their carat weight.   Sometimes a poorly cut diamond with a fat girdle to preserve carat weight is a sacrifice over getting the most brilliance out of a stone, so beware. A diamond may be larger but poorly cut, or have a poor make, so a smaller more well-cut diamond may be worth more.

At diamondcrownjewelry.com, only the finest quality diamond jewelry is sold, and you can be assured that our loose diamonds are genuine and untreated unless otherwise stated. We have a variety of diamond jewelry from earrings, necklaces, mens diamond rings, pendants, and real diamond rings, including colored diamonds. If you can't find what you're looking for, we can custom design a ring, pendant or other jewelry to your specifications. We even offer services such as appraisals and "appraisal parties".
When you make an investment in one of our diamond purchases, you can have the peace of mind that you're getting the best genuine diamond jewelry in the best solid metal quality at the best price.

Shop by Category

Diamond Earrings

Loose Diamonds

Diamond Necklaces

Diamond Pendants

Mens Diamond Rings

Real Diamond Rings

Appraisals

Custom Design

Sales and Promotions

Cubic Zirconia (CZ) Collection

Do you have Real Diamond Rings?

Diamond Grading Guide

Ring Sizer Guide

CZ & Sterling Silver info

A Canadian Diamond's Story

Price Set

Cart

Contact Information