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Lab-Grown Diamonds, Explained

How they are grown, how experts tell them from mined diamonds, and what to ask in Singapore showrooms

Lab-grown diamonds have taken a large share of Singapore\'s diamond counter: identical in chemistry to mined diamonds, grown in weeks instead of formed over geological time, and priced well below natural equivalents. Buyers who understand what they are — and what they are not — negotiate that market with far more confidence.

What a lab-grown diamond actually is

A lab-grown (synthetic) diamond is real diamond — carbon in the diamond crystal structure — not cubic zirconia, not moissanite, not a "simulant". Two methods dominate: HPHT (high pressure, high temperature — growth mimicking the Earth\'s mantle) and CVD (chemical vapour deposition — carbon layering onto a seed plate in a plasma chamber). Simulants merely look like diamond; synthetics are diamond, which is why detection needs instruments, not eyes.

How professionals tell grown from mined

Fluorescence patterns — HPHT-grown stones often show distinctive geometric fluorescence under UV.
Growth striations and inclusions — CVD layering leaves fine striations visible with magnification; metallic flux inclusions can betray HPHT growth.
Spectroscopy — impurity signatures (nitrogen, silicon-vacancy centres common in CVD) read in the laboratory; this is the decisive test.
Screening instruments — modern diamond screeners (the type used in GT200 training) flag stones for laboratory confirmation.

Every lab-grown diamond sold legitimately must be disclosed as such and is typically laser-inscribed on the girdle and noted on its certificate (IGI and GIA both grade lab-growns; Singapore retailers commonly sell with IGI certificates).

Buying questions for any Singapore showroom

Is this stone natural or lab-grown — and where is that stated on the certificate?
Who graded it, and is the girdle inscription matched to the report number?
What is the resale or trade-in policy? (Lab-grown pricing has trended down as production scales — treat it as a purchase to wear, not an asset.)
For a colourless stone at a surprisingly good price — has it been screened? Ask when "too good to be true" applies.

Where lab-grown sits in gemmology education

Diamond identification has become a two-track skill: the classic 4 Cs, and the grown-vs-mined detection that now dominates laboratory work. Both tracks are taught in JDMIS gemmology — GT100 for value factors and trade practice, GT200 for the instruments and screening workflow. Our free Singapore gem labs guide profiles the laboratories that issue the certificates you will be handed.

Common questions

Are lab-grown diamonds real diamonds?

Yes — they are chemically and crystallographically diamond. They differ in origin (weeks in a reactor versus geological time), and in price. Disclosure on certificates is mandatory.

Can you tell a lab-grown diamond by eye?

No. Even jewellers cannot separate them reliably by eye; it takes fluorescence patterns, magnification of growth features and spectroscopy. Screening instruments flag candidates; laboratories confirm.

Do lab-grown diamonds come with certificates in Singapore?

Legitimate lab-grown sales include disclosure and grading — commonly IGI or GIA lab-grown reports, with the report number laser-inscribed on the girdle.

Learn this properly — gemmology at JDMIS, Singapore

Everything on this page is taught hands-on at JDMIS with real stones:

Gemmology: Secrets of the Gem & Jewellery Trade (GT100) — covers diamonds alongside coloured stones — the value factors, the treatments and the trade distinctions, including where lab-grown sits
Gem Identification Methods (GT200) — hands-on instrument work: refractometer, specific gravity, microscope and UV, the way professionals actually identify stones.

Free tools while you read: Gem Globe (where stones come from) · Name That Gem (test your eye) · our guide to every Singapore gem laboratory.

Educational content by the gemmology faculty of the Jewellery Design & Management International School (JDMIS), Singapore. Gemmological constants quoted are standard reference values.