Diamond Guide

Choose a diamond by how it looks, how it sits in the setting and the details of the individual stone. This guide explains the terms you will see while exploring the collection.

Understand the 4Cs

• Cut: how proportions and finishing influence the way a diamond interacts with light.
• Colour: for diamonds on the D-to-Z scale, the relative absence of colour.
• Clarity: the presence of internal inclusions and surface blemishes.
• Carat: the weight of the diamond, rather than its diameter.

Carat weight and appearance

Two diamonds of the same weight can look different in size because their shape and proportions differ. Compare the measurements and the setting as well as the carat figure. Ask whether a stated weight refers to the centre stone or the combined weight of multiple stones.

Natural and laboratory-grown diamonds

Confirm the origin of the individual stone you are considering. Learn about laboratory growth methods in our CVD and HPHT guide.

Check the selected specification

Metal, size, carat and certificate options can vary between products. Where a laboratory report is included, ask for the report details for the selected stone. A generic product photograph does not replace its individual specification.

For independent background reading, explore GIA’s guide to the 4Cs.

Continue exploring

All jewellery guides · Selected pieces · Private consultation