Our Guide to Buying Diamonds
Exquisite, beautiful and truly unique; diamonds are the perfect way to express love and commitment to that special someone.
We believe when it comes to purchasing diamonds it is a truly personal experience and therefore it is important to firstly consider the 4 C’s: carat, clarity, cut and colour, alongside other important factors such as shape and certification. By offering some of the highest quality diamonds from reputable international suppliers and working smarter and more efficiently, we can provide products which are excellent value for money.
Here at Austen & Blake we understand that choosing the right diamond can be a daunting and lengthy process, so here we have composed a simple guide to help. If you have any further questions, however, please contact our Customer Care team.

Carat
The carat of a diamond is determined by the weight rather than the actual size. Using that theory this would mean that the larger the carat, the heavier the diamond.
It is important to consider the carat and cut together when making a purchase. A larger carat diamond with a poor cut grade can appear smaller than a diamond of the same size with a higher cut grade.
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FL
VVS2
VS1
SI1
Clarity
Diamond clarity is the assessment of imperfections on the surface or within the diamond. Inclusions are internal defects and are very common within most diamonds whereas flaws to the surface are known as blemishes. Diamonds with the least amount of defects will have a higher clarity grading.
Inclusions can appear black, grey or white in appearance and are graded under x10 magnification. Five grading factors which are considered are:
- • The size of the inclusions
- • Number of inclusions
- • Position of the inclusions
- • Colour and relief of the inclusions
- • Nature of the inclusions
Most diamonds are imperfect, however, our most popular grade is VS1 - VS2 due to appearing almost flawless to the naked eye, making them a good value option.

Cut
Not to be confused with the shape or size of the diamond, the cut is all about proportions. A well-cut diamond reflects light and brilliance to ensure maximum sparkle, and is possibly the most important factor to consider when purchasing diamonds. Even a diamond with perfect clarity and colour grade can appear dull if it has been cut poorly.
Diamonds which are cut in equal proportion enable light to be returned out of the top, producing the signature sparkle. If they are cut too deep then light is transferred out of the side whereas too shallow and light will return from the bottom creating a less lustrous appearance.
Grades are assigned using the diamond cut grade guidelines established by the Gemological Institute of America. Diamonds which are assigned ideal, excellent or very good cut grades are considered well cut.
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D E F
-
G H I J
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K L M
Colour
Colour is another very important factor to consider when choosing diamonds. Rarity and purity are measured by a diamond’s lack of colour. Higher quality diamonds will have a pure, bright white appearance whereas those lower in quality will have noticeable colour, and to the untrained eye this can be tricky to spot.
In the mid-1950s The Gemological Institute of America devised a colour grade scale between D-Z, to regulate and define the colour spectrum of diamonds. With D being completely colourless and Z being slightly yellow or brown in appearance. The colour of the diamond has a huge impact on its value.
However, this rule is not to be confused with coloured diamonds. Coloured diamonds are graded on a separate diamond colour scale and can even be more rare or valuable than the diamond.
Shape
Diamonds come in a variety of shapes, making this a very personal choice. Not to be confused with cut, the diamond shape refers to the shape it was cut into, and influences the entire look and feel of the diamond.
Round diamonds tend to show more brilliance and scintillation than other shapes and are a popular choice due to their timeless appeal, however, personal preference should prevail when choosing your ideal shape.
Shape
Diamonds come in a variety of shapes, making this a very personal choice. Not to be confused with cut, the diamond shape refers to the shape it was cut into, and influences the entire look and feel of the diamond.
Round diamonds tend to show more brilliance and scintillation than other shapes and are a popular choice due to their timeless appeal, however, personal preference should prevail when choosing your ideal shape.
Shape
Diamonds come in a variety of shapes, making this a very personal choice. Not to be confused with cut, the diamond shape refers to the shape it was cut into, and influences the entire look and feel of the diamond.
Round diamonds tend to show more brilliance and scintillation than other shapes and are a popular choice due to their timeless appeal, however, personal preference should prevail when choosing your ideal shape.
Shape
Diamonds come in a variety of shapes, making this a very personal choice. Not to be confused with cut, the diamond shape refers to the shape it was cut into, and influences the entire look and feel of the diamond.
Round diamonds tend to show more brilliance and scintillation than other shapes and are a popular choice due to their timeless appeal, however, personal preference should prevail when choosing your ideal shape.
Shape
Diamonds come in a variety of shapes, making this a very personal choice. Not to be confused with cut, the diamond shape refers to the shape it was cut into, and influences the entire look and feel of the diamond.
Round diamonds tend to show more brilliance and scintillation than other shapes and are a popular choice due to their timeless appeal, however, personal preference should prevail when choosing your ideal shape.
Shape
Diamonds come in a variety of shapes, making this a very personal choice. Not to be confused with cut, the diamond shape refers to the shape it was cut into, and influences the entire look and feel of the diamond.
Round diamonds tend to show more brilliance and scintillation than other shapes and are a popular choice due to their timeless appeal, however, personal preference should prevail when choosing your ideal shape.
Shape
Diamonds come in a variety of shapes, making this a very personal choice. Not to be confused with cut, the diamond shape refers to the shape it was cut into, and influences the entire look and feel of the diamond.
Round diamonds tend to show more brilliance and scintillation than other shapes and are a popular choice due to their timeless appeal, however, personal preference should prevail when choosing your ideal shape.
Shape
Diamonds come in a variety of shapes, making this a very personal choice. Not to be confused with cut, the diamond shape refers to the shape it was cut into, and influences the entire look and feel of the diamond.
Round diamonds tend to show more brilliance and scintillation than other shapes and are a popular choice due to their timeless appeal, however, personal preference should prevail when choosing your ideal shape.
Shape
Diamonds come in a variety of shapes, making this a very personal choice. Not to be confused with cut, the diamond shape refers to the shape it was cut into, and influences the entire look and feel of the diamond.
Round diamonds tend to show more brilliance and scintillation than other shapes and are a popular choice due to their timeless appeal, however, personal preference should prevail when choosing your ideal shape.
Shape
Diamonds come in a variety of shapes, making this a very personal choice. Not to be confused with cut, the diamond shape refers to the shape it was cut into, and influences the entire look and feel of the diamond.
Round diamonds tend to show more brilliance and scintillation than other shapes and are a popular choice due to their timeless appeal, however, personal preference should prevail when choosing your ideal shape.

IGI

GIA
Certificate
At Austen & Blake confidence and credibility is important to us, therefore we provide diamond certification for every diamond in which we sell.
A diamond certification is an impartial summary of the authenticity of a diamond and the specifications such as carat, clarity and cut etc, carried out by expert gemologists or diamond laboratories. This document is important as it provides the purchaser with reassurance that the diamond is as described by the seller.
Austen & Blake: Free of charge and issued by our in-house gemologist. This certificate displays carat weight, colour, clarity of the diamonds, design number and diamond shapes (multi-stone options).
EGL (European Gemological Laboratory): A third party option who are one of the few laboratories to group grade readymade jewellery products, for example, our multi-stone products such as Tennis bracelets and Eternity Rings.
IGI (International Gemological Institute) and GIA (Gemological Institute of America): World-renowned independent labs who are considered to be the strictest in the industry.
Certificates will display carat weight, colour, clarity, diamond shape, cut, polish, symmetry, fluorescence levels, types of inclusions and certificate number.
As your certificate provides invaluable security in the case of loss, trade or resale, it is important to keep this document safe. Whenever the diamond may leave your possession (for example, to be cleaned) it is a good idea to remind the party taking possession of the diamond that you have a certificate. This should remove any temptation of third-party fraud.