Engagement Ring Guide

Choosing a Diamond

Carat, color, clarity and cut decide what a diamond is worth. Learn what each grade actually means, and where paying more genuinely shows in the stone.

A round brilliant-cut diamond standing upright, with smaller loose diamonds behind it.

Diamonds come in every size and in a range of shapes, colors and internal characteristics, and their value is determined by those characteristics - so what is the world of diamonds? Let's find out.

The quality and price of a diamond are defined by the four Cs: carat, color, clarity and cut. Understanding how each one works, and how they balance against one another, is the key to choosing a stone that looks its best for your budget. Each C is covered in its own guide:

  • Diamond weight - Carat
  • Diamond color - Color (with the full D-to-Z color chart)
  • Diamond clarity - Clarity (with the full clarity scale)
  • Diamond cut - Cut

Once you understand the four Cs, the single most useful habit is to compare like with like: look at certified loose diamonds (opens in new tab) of similar weight and grade side by side, and always start from a stone that carries an independent grading report (opens in new tab). Many buyers also find that purchasing closer to the source - directly from a manufacturer or established diamond supplier rather than through several middlemen - makes that comparison easier, with a wider selection and clearer, more transparent pricing.