Other factors that shape a diamond's value

Last updated 2026-05-12

Beyond the 4Cs — fluorescence, symmetry, polish, girdle, inclusions, and certification. The signals Gems Mart Jewellers weighs alongside the headlines.

Other factors Gems Mart Jewellers considers for you

Apart from the 4Cs, the following factors also affect a diamond's brilliance and price.

Fluorescence

Can affect a diamond's appearance under UV light or daylight, sometimes making it cloudy or enhancing whiteness.

Symmetry

Well-aligned facets improve light reflection and brilliance, increasing the value.

Polish

A smooth surface boosts brilliance; poor polish can dull the diamond and reduce its price.

Girdle thickness

Affects durability and how large the diamond appears, influencing price.

Inclusions / blemishes

Type and position affect appearance and value; central inclusions lower price more.

Certification

Grading labs vary in terms of strictness of grade. Some certifications allow for a premium resale or a more reliable excellence.

Why our diamonds are different

Our diamonds are sourced from primary cutters and suppliers with careful selection from various diamond lots to ensure exceptional quality at better than market prices. We prioritise responsible practices from the suppliers, offering you diamonds that are both stunning and ethically crafted.

Transparency has been a part of our DNA for generations. As the family jeweller, we're dedicated to helping you make an informed decision when purchasing a diamond. We invite you to compare loose diamonds side by side, so you can choose the one that truly speaks to you. We're here to answer your questions and guide you every step of the way.

Conflict-free and ethically sourced

We have been ethically sourcing diamonds since 1999. You can trust that your diamond is conflict-free and feel confident knowing your purchase is genuine.

Conflict diamonds have been almost completely eliminated from the market because of the UN-mandated Kimberley Process, an international certification process established in 2003. Through the Kimberley Process, 82 countries work cooperatively to prevent conflict diamonds from entering the rough diamond trade. Today, the Kimberley Process also focuses on addressing the social and economic challenges affecting diamond communities.