4Cs color

Diamonds are graded on a scale that runs from colourless to light yellow or brown. The closer a stone sits to the colourless end, the rarer it is and the more it costs. Much of the diamond market steers buyers a little way down that scale to save money, because a colourless mined diamond carries a steep premium. This guide explains the whole scale so you understand what that trade involves, and why Ronora does not make it.

Diamond colour runs from strongly tinted to completely transparent.

• Colourless diamonds are the top of the scale, and the rarest.
• Near colourless diamonds follow, and can still look very good in the right shape and metal.
• Tinted diamonds carry a visible warmth, usually yellow.
  
  

Colour is graded from D, which is colourless, down to Z, which is yellow-brown. The closer a diamond's grade is to D, the more valuable it is. Ronora sells the top three grades only: D, E and F.

D is the top of the scale, with no detectable colour at all. E and F are also colourless, and even trained graders struggle to separate the three without controlled lighting and a master set to compare against. Face up, on a hand, in ordinary light, they look the same.

Below the colourless range sit the near colourless grades. G and H look colourless most of the time, and the average person will not pick an H out of a line-up against a D. Professionals often need magnification and a comparison stone to separate a G from a D.

I and J carry more warmth. That tint becomes visible in step-cut shapes such as the Asscher and emerald, where the long open facets show everything, and in elongated shapes such as the oval or elongated cushion where colour concentrates at the ends.

Most diamond retailers will tell you to drop into the near colourless range and disguise the difference. The usual advice runs:

• Take a G or H and set it in rose or yellow gold, because a warm metal masks a warm tint.
• Choose a brilliant cut such as the round, oval or marquise, because rapid sparkle hides slight colour.
• Put the saving into cut, since a well cut stone returns more light and disguises more.

All three points are true, and for a mined diamond the advice is sound, because the jump from G to D can add a great deal to the price. It is worth understanding so you can judge what other sellers are offering you.

The masking tricks above stop working in four situations:

• A step cut such as the Asscher or emerald, where open facets show everything.
• A white gold or platinum setting, which exposes warmth instead of softening it.
• Any stone above two carats, where colour concentrates and becomes far easier to see.
• An elongated outline, where tint gathers at the points.
  
  

This is a large part of why Ronora holds to D-E-F across the whole collection. It means the shape, the metal and the carat weight are all free choices, with no combination that quietly exposes a compromise made on colour.

At Ronora the question does not really arise, because the answer is already fixed. Every diamond we sell sits in the D-E-F colourless range. We do not stock G or below in any shape, any carat weight or any metal.

We can do that because our stones are lab grown. The premium that makes a colourless mined diamond so expensive largely disappears, so there is no reason to trade colour away to protect a budget. You get the top of the colour scale as standard, and your money goes into carat weight and shape instead.