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Loose round brilliant lab-grown diamond held by tweezers on white studio

Can You Tell Lab-Grown Diamonds Apart From Real Diamonds?

September 14, 20265 min readBy Layla Al Ansari

Can you tell lab-grown diamonds apart from real diamonds? Your eye usually cannot. A lab grown diamond is diamond. IGI-certified reports mark laboratory-grown origin. R Rumi Diamond sets those stones only.

In This Guide

  1. 01Can You Tell Lab-Grown Diamonds Apart From Real Diamonds?
  2. 02What people mean by "real"
  3. 03What a tester and a loupe can do
  4. 04What IGI-certified puts on paper
  5. 05Lab grown vs real diamond on the hand
  6. 06Growth method is not a party trick
  7. 07What to ask anyway
01

Can You Tell Lab-Grown Diamonds Apart From Real Diamonds?

The search can you tell lab grown diamonds apart from real diamonds mixes two ideas. One is whether the stone is diamond at all. The other is whether laboratory-grown can be split from mined by eye.

Your unaided eye will not print origin. A 10x loupe usually will not either. Screening sits with the grading lab. That is the honest core of this category.

A lab grown diamond is real diamond in the materials sense: carbon, Mohs 10, the same family of light return you already call diamond. Real, in shop slang, often gets used as a stand-in for mined. We prefer two labels: laboratory-grown diamond, or mined diamond.

At R Rumi Diamond we set IGI-certified lab-grown diamonds only. We answer this with the stone under a light and the report on the table.

02

What people mean by "real"

Plenty of buyers hear real and hear natural. Natural, in a jeweller's mouth, means mined. Real means the material is diamond. Mined stones are natural diamond. A lab grown diamond is laboratory-grown diamond. Either will scratch a sapphire. Either can chip on the girdle if a blow hits at a bad angle.

So, can you tell lab-grown diamonds apart from real diamonds if real means diamond? You are asking the wrong split. The useful split is laboratory-grown versus mined, or diamond versus simulant.

Simulants are the stones that fail as diamond. Moissanite is silicon carbide. Cubic zirconia is an oxide. Those can look flashy in a photo and still fail a proper screen. Listings that borrow the word lab for those materials are why suspicion stays busy.

03

What a tester and a loupe can do

A thermal tester typically reads a lab grown diamond as diamond. Heat moves through that lattice the way it moves through a mined stone. People who type "do lab diamonds pass a diamond tester" next to can you tell lab grown from natural usually get a pass on the thermal probe.

Moissanite can fool an older thermal probe. Jewellers who see both in a week will often run a second check, or open the report and skip the demonstration. We try to.

A 10x loupe will often split diamond from cubic zirconia, because CZ rolls at the facet edges and the weight in the hand feels wrong. The same loupe will not reliably split laboratory-grown from mined. Facet junctions look sharp on both when the cut is sound. The table returns light the way diamond does.

If you hoped your eye would do the origin work, you may notice it cannot. That is ordinary. Origin is laboratory work.

Loose round brilliant lab-grown diamond beside tweezers
04

What IGI-certified puts on paper

An IGI-certified lab grown diamond comes with a report that states laboratory-grown. IGI screens origin first. Mined and laboratory-grown both pass as diamond. A simulant fails that screen.

The 4Cs sit on the same kind of scale used for mined diamond. Colour language uses the D-to-Z scale. Clarity uses the same family of terms you already know. We would rather you see two neighbouring grades in the tray than memorise the letters alone.

Many IGI-certified stones carry a laser inscription on the girdle that matches the report number. Tilt the stone under a 10x loupe and walk the girdle. If stone and paper disagree, we stop.

Do not treat a cropped photo of a certificate as enough. Check the number on IGI's verification page. We would rather you do that while you are still sitting with us.

R Rumi Diamond uses IGI for our stones. The report is the document we hand you. We do not claim a different lab's paper for inventory we grade through IGI.

Round brilliant lab-grown diamond solitaire in white metal
05

Lab grown vs real diamond on the hand

A lab grown diamond engagement ring wears like diamond of the same cut and setting. The claws hold carbon. Soap film dulls it until you wipe it. Sunscreen on the band is still a nuisance.

Round brilliant reads as the familiar outline. Oval stretches light down the finger. Emerald cut shows windows if the cut is lazy. Compare outline and metal before you argue origin. Origin is already on the IGI page.

Yellow gold and white gold change how the edge of the diamond reads against skin. Try both when you can. The stone's origin line does not move.

Buyers who stare for origin cues in the sparkle often invent differences that are cut, proportions, or dirt. Clean the stone. Then look again. Then read the paper.

06

Growth method is not a party trick

Growth is HPHT or CVD. One uses pressure and heat. The other grows from carbon-rich gas on a seed. Skip memorising the reactor if you are shopping for a ring. Read the origin line. If growth method is noted on the report, read that line too. It will not make the stone flash a different colour on your finger.

Advanced lab equipment can sort laboratory-grown from mined after the stone is diamond. That is why shops keep pointing at grading labs instead of stage demos. A confident seller with no paper is not a substitute for a report number you can verify.

Oval lab-grown diamond solitaire in yellow gold
07

What to ask anyway

See the stone next to the IGI-certified report. Match any girdle inscription to the number. Ask the seller to say laboratory-grown or mined in plain words on the ticket.

Ask how your insurer wants the IGI number stored. We try to put a copy of the report in your folder before you leave.

Care stays ordinary. Warm water, mild soap, soft brush if the setting is open. Hardness 10 is not a promise the girdle cannot chip.

If can you tell lab grown diamonds apart from real diamonds is the question you still carry into the room, bring it. The answer is paper and instruments, not a staring contest.

We would rather walk an IGI-certified lab grown diamond through the light with you than sell you a paragraph. Look through R Rumi Diamond lab-grown diamond jewellery, including lab grown diamond engagement ring styles, and ask for the report on any stone that holds you.

Emerald-cut lab-grown diamond solitaire in white metal

Written by

Layla Al Ansari

Luxury Lab-Grown Diamond Specialists

R Rumi Diamond is a luxury jeweller specialising in lab-grown diamonds, bespoke engagement rings, and high jewellery. Our editorial team writes about diamond grading, jewellery care, and how to choose the right stone for your story.

  • Lab-grown diamonds
  • Diamond grading and certification
  • Engagement ring selection
  • Bespoke jewellery design
  • Diamond care and maintenance