Do Lab-Grown Diamonds Get Cloudy or Lose Their Sparkle Over Time?

ZKZ Editorial TeamMain answer · Product & gemmology desk

No. A lab-grown diamond does not age, fade or turn cloudy in normal wear. It is the same crystallised carbon as a mined diamond. When one starts to look milky, the cause is almost always outside the stone: a film of skin oil, soap or lotion on the underside, debris in the setting, or a feature that was already present when it was bought.

Work through the causes in order

1. Residue on the pavilion

Fact A diamond’s brightness depends on light reflecting off its lower facets. Grease is attracted to diamond surfaces, and a thin film there interrupts that reflection, so the stone looks flat even though nothing has changed inside it. This is the most common cause and the easiest to fix.

2. Debris in the setting

Prongs and closed-back settings trap soap and dust under the stone. In sterling silver pieces, tarnish on the surrounding metal also makes the whole piece look duller.

3. Something that was there from the start

Clarity characteristics, haziness from growth features, or a poorly proportioned cut are present from the day the stone is made. They do not develop later, but you may notice them only once the novelty wears off. A grading report, if you have one, records clarity at the time of grading.

How to clean it safely

1. Soak for 15 to 20 minutes in warm water with a few drops of mild dish soap.
2. Brush under the stone with a soft toothbrush, where residue collects.
3. Rinse in clean water with the drain closed, then dry with a lint-free cloth.
4. Check in daylight. If the stone is bright again, residue was the cause.

Where the limits are

Our advice Avoid harsh silver dips and abrasive pastes on plated silver, because they can strip the finish. Be cautious with ultrasonic cleaners on pavé or older settings: the diamond tolerates it, but vibration can loosen small stones.

When to stop If a stone stays cloudy after a proper clean, or looks chipped or loose, stop wearing it and have a jeweller inspect it under magnification. Some lab-grown diamonds receive post-growth treatment, which should be disclosed on a report. If you suspect something has changed, a laboratory, not a home test, is the way to confirm it.

Sources

• GIA, Gems & Gemology (Summer 2024): Laboratory-Grown Diamonds, an update on identification
• FTC: In the Loupe, advertising diamonds, gemstones and pearls

Fact = stated by the cited source. Our advice = editorial recommendation. Uncertain / it depends = limits of what can be said in general.