Diamonds 101: A Beginner's Guide to Understanding Diamonds
Understanding Diamonds: Where to Begin
Buying a diamond can feel overwhelming, especially for first-time buyers. With so many factors affecting quality and price, it is easy to feel lost. But it doesn't have to be complicated. Corelune Jewellery's beginner's guide to diamonds will give you the knowledge you need to shop with complete confidence.
The 4Cs: The Universal Standard for Diamond Quality
Every diamond is assessed using four key criteria, known as the 4Cs:
- Cut: The most important of the 4Cs. Cut determines how well a diamond reflects light — its sparkle and brilliance. An excellent cut diamond will outshine a larger diamond with a poor cut.
- Colour: Diamonds are graded on a colour scale from D (colourless) to Z (light yellow or brown). Colourless diamonds (D–F) are the rarest and most valuable, but G–J diamonds appear nearly colourless to the naked eye and offer excellent value.
- Clarity: This refers to the presence of inclusions (internal characteristics) and blemishes (surface characteristics). The scale runs from FL (flawless) to I3. Many inclusions are invisible to the naked eye — an SI1 or SI2 diamond can appear flawless in person.
- Carat: Carat is a measure of weight, not size. One carat = 0.2 grams. Larger carat diamonds are rarer and more expensive, but a well-cut smaller diamond will often look more impressive than a poorly cut larger one.
Diamond Shapes
Diamonds are cut into many different shapes:
- Round Brilliant: The most popular shape. Maximises sparkle and brilliance.
- Princess: Square with pointed corners. Modern and elegant.
- Oval: Elongates the finger and appears larger than its carat weight suggests.
- Cushion: Rounded corners and a vintage feel.
- Emerald: Rectangular with step cuts. Emphasises clarity over brilliance.
- Pear, Marquise, Heart: Distinctive shapes for a more unique look.
Diamond Grading Certificates
Always ask for a grading certificate from a reputable laboratory when purchasing a significant diamond. The main grading labs are GIA (Gemological Institute of America) and IGI (International Gemological Institute). A certificate is your guarantee of the stone's quality grade.
Come and speak to the team at Corelune Jewellery — we are always happy to walk you through every aspect of diamond buying, with no pressure and complete honesty.







