The short answer: a colour treated lab grown diamond is a lab grown stone whose colour has been changed or enhanced after it was grown, or that gets its colour through the way it was made. A trustworthy seller and a good report will tell you which, so you know exactly what you are buying.
Lab grown diamonds come in colourless stones and in fancy colours such as pink, blue and yellow. Some of those colours are produced during growth, and others are created or deepened by treatment afterwards. Neither is hidden when the stone is described honestly.
How colour is created
- During growth: trace elements added while the diamond grows can give it a colour, such as blue.
- After growth: processes such as irradiation and heating can create or change colour, for example pink or yellow tones.
Our guide to diamond treatments explained covers the processes in more detail.
Colourless stones can be treated too
Some lab grown stones are treated after growth to improve their colour grade. Reports commonly mention this, and it should be disclosed.
Is treatment a problem?
Treatment is not necessarily a problem, and many fancy colour diamonds, natural and lab grown, are enhanced. What matters is disclosure. You should know what has been done and be able to find it on the report, and we help you read the wording.
Natural fancy colours
Natural fancy colour diamonds are rare and can be very costly, particularly pink and blue. Many natural coloured diamonds on the market are also enhanced, and a report should say so. Lab grown fancy colours make these shades available at a far lower price, and they let more people choose colour. See why Argyle pink diamonds are so rare for the natural side of the story.
Is the colour permanent?
For the common treatments the colour is generally stable in normal wear, though extreme heat can affect some enhanced colours. We can talk through any care points for a specific stone. A jeweller who needs to solder or repair a ring should be told that the stone is treated.
Treatment and repairs
Because some treated colours can be affected by high heat, any work on the ring, such as resizing or retipping a claw, needs a little extra care. A jeweller may protect the stone or remove it before using a torch near it. Keep the report with the ring, so whoever works on it knows exactly what the stone is. See what happens at a ring service appointment.
What to ask a seller
- Was the colour created during growth or after?
- Is the treatment stated on the report?
- Does the report number check out on the lab's website?
Choosing a fancy colour
Pink, blue and yellow stones are a beautiful way to make a ring individual. They suit bespoke designs well because the setting can be built around the colour. See lab grown fancy colour diamonds and browse the lab grown fancy colour diamonds collection. Nothing is made until you approve the design in writing, and our standard making time is 5 to 6 weeks, which can vary with your location and how busy we are. Pieces start from £600.
Frequently asked questions
Are colour treated diamonds real diamonds? Yes, treatment changes colour, not the fact that the stone is a diamond.
Will the colour fade? It is generally stable in normal wear, and we explain any care points.
Do treated stones cost less? It depends on the stone, and we help you compare options.
Does a report show treatment? Reports commonly mention it, and we help you find the line.
Can a treated stone be resized in a ring? Yes, with care, so tell the jeweller about the treatment first.