Roger Summers Jewellery - Goldsmith - London
  *Home | About me | Gallery | Diamond Quality | Reviews | Contact me


Uncut diamonds

Uncut diamonds

Un cut diamond


Cut diamonds

Revolving diamond image
Diamond grading chart

Cut diamond brilliance


Coloured precious stones

Precious stones




Roger Summers also manages Medieval shows around the Uk and abroad. His website is chosing a diamond remember the 4C's:


Diamond colour grades

Colorless diamonds are the most desirable since they allow the most refraction of light (sparkle). Off white diamonds absorb light, inhibiting brilliance.

Diamonds graded D through F are naturally the most valuable and desirable because of their rarity. Such diamonds are a treat for the eyes of anyone. But you can still obtain very attractive diamonds that are graded slightly less than colorless. While a hint of yellow will be apparent in diamonds graded J through M, this color can often be minimized by carefully selecting the right jewellery in which to mount your diamond. Keep in mind that, while most people strive to buy the most colorless diamond they can afford, there are many people who actually prefer the warmer glow of lower-color diamonds. They are graded as follows for quality.

Diamond colour grades
Rough cut diamond grading chart

Diamond Cuts

The "diamond cut" is used is to describe the reflective qualities of a diamond. The more reflective, the more brilliance.

Diamond cut is perhaps the most important of the 4 Cs. A good cut gives a diamond its brilliance which is the brightness that seems to come from the very heart of a diamond. The angles and finish of any diamond are what determines its ability to handle light, which leads to brilliance.

In a poorly cut diamond, the light that enters through the table reaches the facets and then 'leaks' out from the sides or bottom of the diamond rather than reflecting back to the eye. Less light reflected back to the eye means less brilliance.

Uncut and cut diamond

Uncut and cut diamond

There are different types of cuts available too which are shown below.Some cuts are more expensive than others.

Diamond shapes

A Brilliant cut diamond or other gemstone is cut in a particular form with numerous facets to give it exceptional brilliance. The shape resembles that of a cone and provides maximized light return through the top of the diamond.

Brilliant cut diamond detail diagram

Diamond Carat

The word "carat" is taken from the carob seeds that people once used to balance scales. A carat is the unit of weight by which a diamond is measured. One carat is equal to 200 milligrams or 0.2 grams. Because large diamonds are found less commonly than small diamonds the price of a diamond rises hugely to its size.

Diamond sizes in carat

Diamond Clarity

A diamond's "clarity" grade is about the flaws or lack of flaws within it. There are two types of flaws:

Blemishes: found on the surface of the diamond
Inclusions: found within the diamond

"Inclusions" are flaws such as air bubbles, cracks and non-diamond minerals found within the diamond. "Blemishes" are scratches, pits, and chips (some blemishes occur during the cutting process, most often at the girdle).
Because they are less common, diamonds with no or few inclusions and blemishes are more highly valued and priced.

F (Flawless): No internal or external flaws. Extremely rare, these diamonds come with a price tag to match their rarity.

IF (Internally Flawless): No internal flaws, but some surface flaws. Rare but affordable for many people.

VVS1-VVS2 (Very Very Slightly Included 1 and 2): Minute inclusions very difficult to detect under 10x magnification by a trained gemologist. Easy to find in a wide range of prices.

VS1-VS2 (Very Slightly Included 1 and 2): Minute inclusions seen only with difficulty under 10x magnification. Easy to find in a wide range of prices.

SI1-SI2 (Slightly Included 1 and 2): Minute inclusions are visible under 10x magnification and may be visible by the unaided eye. Easy to find in a wide range of prices.

I1-I2-I3 (Included 1, 2, and 3): Inclusions visible under 10x magnification as well as to the human eye. We do not recommend buying diamonds in any of these grades.


Golden Eagle Jewellery logo - Assay Office London Logo