When it comes to buying jewellery featuring gemstones, understanding the quality of the stones is essential. Whether you're purchasing a sapphire, emerald, ruby, or any other precious gem, knowing how to assess its quality can ensure you’re getting both beauty and value. Here’s everything you need to know about gemstone quality and what to look for when choosing your next piece!

The Four Cs of Gemstone Quality 

Much like diamonds, gemstones are evaluated based on a set of criteria known as the Four Cs: Colour, Clarity, Cut, and Carat. Each of these factors contributes to the overall appearance and value of the gemstone.

1. Colour 

The colour of a gemstone is often the most defining characteristic and has the greatest impact on its value. Gemstone colour is evaluated based on three components: hue, tone, and saturation. 

• Hue: This refers to the basic colour of the gemstone, such as blue for sapphires or green for emeralds. 
• Tone: Tone measures the depth of the colour, ranging from light to dark. ● Saturation: Saturation reflects the intensity of the gemstone's colour. A gemstone with vivid and intense colour saturation is more desirable and valuable than one with weak or dull hues. 

When buying coloured gemstones, aim for a stone with a pure hue, medium to dark tone, and vibrant saturation for the best quality. 

2. Clarity 

Clarity refers to the presence of any inclusions (internal flaws) or blemishes (external flaws) within the gemstone. While some inclusions are natural and expected, particularly in gems like emeralds, fewer inclusions generally lead to a higher-quality stone. 

Unlike diamonds, where clarity is a significant factor, many coloured gemstones are more forgiving of inclusions, especially if the inclusions do not interfere with the gem’s brilliance. However, gems with fewer visible inclusions are still more valuable. 

3. Cut

The cut of a gemstone affects how light reflects within it, contributing to its overall brilliance and sparkle. A well-cut gemstone will have symmetrical facets that reflect light evenly, making it more attractive. 

A poor cut can make even a high-quality gemstone look lacklustre. So, be sure to look for gemstones with expert cuts that highlight their natural beauty. 

4. Carat 

Carat refers to the weight of the gemstone rather than its size. Larger gemstones are rarer and often more valuable, but the quality of the colour, cut, and clarity is just as important when assessing the gemstone's overall worth.