Round Lab Grown Diamonds

What is a round lab grown diamond?

A round lab grown diamond is chemically, physically and optically identical to a mined round brilliant, produced in a controlled laboratory environment rather than extracted from the earth. The two primary growth methods — High Pressure High Temperature (HPHT) and Chemical Vapour Deposition (CVD) — replicate the conditions under which natural diamonds form, yielding a genuine carbon crystal graded against the same four-carat criteria. The round brilliant cut itself is engineered around 57 or 58 facets arranged to maximise the return of white light through the table. Because the proportions are so thoroughly studied — ideal depth percentages sit between approximately 59% and 62.5%, with a table between 54% and 58% — a well-cut round lab grown diamond will consistently achieve very good or excellent cut grades on a GIA, HRD or IGI certificate. The lab origin changes nothing about that optical performance.

How does a round lab grown diamond compare to a mined round brilliant?

A certified round lab grown diamond and a certified mined round brilliant are graded against identical standards — no gemological instrument distinguishes one from the other by appearance alone. The practical differences are in provenance and price per carat. Round lab grown diamonds typically offer a materially larger stone for a given budget: the same spend that yields a 0.75ct mined round brilliant may reach a 1.25ct or 1.5ct lab grown stone of comparable colour and clarity. For buyers where long-term resale value is a priority, natural rounds have an established secondary market; lab grown diamonds are newer to that market. For buyers prioritising size, specification, and reduced environmental footprint of extraction, round lab grown diamonds are the more practical route. Both are neutral offerings at President Jewellers — the right choice depends entirely on the buyer's own priorities.

What certification should a round lab grown diamond carry?

Every round lab grown diamond sold by President Jewellers is certified by GIA, HRD or IGI — three of the most widely recognised independent grading laboratories. A grading report for a round lab grown diamond will document the four Cs: carat weight, colour (graded on the D-to-Z scale), clarity (from Flawless to I3), and cut grade (critical for a round brilliant, where proportions and symmetry directly govern light return). The report will also confirm the growth method — HPHT or CVD — and note any post-growth treatment. When a certified round lab grown diamond is set into one of our rings, the completed piece is hallmarked at the London Assay Office. Purchasing loose carries a 30-day return window, no questions asked, no exclusions.

What does a round lab grown diamond cost in the UK?

Round lab grown diamond prices are set by carat weight, cut grade, colour and clarity — the same drivers as mined rounds, though the per-carat price sits considerably lower. A well-specified 1.0ct round lab grown diamond in the G–H colour range with VS2 clarity represents a significantly lower outlay than its mined equivalent, which is why round lab grown stones have become a practical route for buyers with a defined budget. Bridebook's 2026 UK average engagement ring spend of £2,247 illustrates the context: for many buyers, selecting a round lab grown diamond allows a meaningfully higher carat weight or clarity grade within that figure. Price also responds to cut grade — an excellent-cut round lab grown diamond commands a premium over a very good cut, and that investment is usually worthwhile given how directly cut governs a round brilliant's performance.

How to choose a round lab grown diamond for daily wear

Round lab grown diamonds score 10 on the Mohs hardness scale — the hardest material available for jewellery. A round brilliant's absence of sharp corners or pointed tips (unlike pear, marquise or princess cuts) makes it among the most resilient shapes for a stone set into a ring worn daily. When choosing a round lab grown diamond for a ring, the cut grade warrants the most attention: it is the single factor most visible to the unaided eye, governing how the stone handles ambient light. Colour and clarity can be balanced more freely — a G or H colour in an eye-clean VS2 or SI1 round lab grown diamond will face up white and clean in most settings. If the stone is later set into one of our rings, the process moves to CAD design and a wax or silver sample for try-on at the Hatton Garden workshop, with a 7–14 working day lead time before the finished, hallmarked ring is delivered on complimentary insured UK delivery.