Lab diamonds are real diamonds grown above ground. Using high heat and pressure or carbon-rich plasma, scientists turn pure carbon into the same crystal structure found in mined diamonds. The result matches natural diamonds in chemistry, hardness and brilliance — the difference is origin, not substance. And to clear up a common confusion: lab diamonds are not simulants like moissanite or cubic zirconia; they’re genuine diamonds that can be set, worn and graded just like the ones formed in the Earth.

In this guide, you’ll learn what “lab-grown” truly means: whether lab diamonds are real, how HPHT and CVD growth work, how lab and natural stones compare, and how professionals tell them apart. We’ll map UK pricing and resale considerations, show you how to choose quality with the 4Cs, and explain which certificates to trust (GIA vs IGI). You’ll also find practical insights on ethics and energy use, available shapes and colours, settings and care, plus buying tips to avoid pitfalls. Finally, we’ll share how A Star Diamonds can help you choose or create a ring that fits your style and budget.

Are lab diamonds real diamonds?

Yes—lab diamonds are real diamonds. They’re pure carbon crystals with the same atomic structure as mined stones, which is why they share identical physical, chemical and optical properties. They score 10 on the Mohs scale, exhibit the same brilliance and fire, and they pass diamond testers because, simply, they are diamonds.

The difference is origin. Natural diamonds formed over geological time; lab-grown diamonds are created in controlled conditions that replicate that process. To the eye—and even under a jeweller’s loupe—they’re indistinguishable. Only specialist laboratory equipment can separate lab-grown from natural by detecting growth features or trace elements.

Lab diamonds aren’t simulants like moissanite or cubic zirconia; they’re graded and certified to the same standards. Next, here’s how they’re made using HPHT and CVD.

How lab diamonds are made: HPHT and CVD explained

Modern labs grow diamonds in weeks using two proven methods that replicate nature: HPHT and CVD. Both start with a tiny diamond “seed” and pure carbon. Under extreme conditions, carbon atoms bond in the same crystal lattice as natural diamonds, creating genuine gemstones that are later cut and polished like any mined stone.

HPHT (High Pressure High Temperature)

HPHT recreates the Earth’s mantle. A diamond seed sits within a press alongside a carbon source. Intense pressure and heat drive carbon to crystallise onto the seed, building a rough diamond layer by layer. Once grown, the crystal is cut and graded in exactly the same way as a natural diamond. The result is a real diamond with identical physical, chemical and optical properties.

CVD (Chemical Vapour Deposition)

CVD uses a vacuum chamber filled with carbon‑rich gas. Energy turns the gas into plasma, freeing carbon atoms that settle onto a flat diamond seed and grow a diamond in ultra-thin layers. Some CVD diamonds may receive post‑growth treatment to refine colour, as noted by industry guides. Either way, both CVD and HPHT produce authentic diamonds; only specialist lab equipment can distinguish growth features. For buyers, the priority is quality (cut, colour, clarity, carat), not the growth method.

Lab-grown vs natural diamonds: properties, similarities and differences

Put a lab-grown and a natural diamond side by side and, once cut and polished, they behave the same. Both are pure carbon crystals with identical chemistry and optics, score 10 on the Mohs scale, and pass diamond testers because they are diamonds. The key differences are how they’re formed and what that means for trace elements and price: lab diamonds grow in weeks and typically cost 60–85% less than natural diamonds of the same grades, as UK jewellers report.

• Chemistry & structure: Identical carbon lattice; lab diamonds are real diamonds.
• Performance: Same hardness, brilliance and fire; graded by the same 4Cs.
• Origin: Nature forms diamonds over billions of years; labs replicate the conditions in controlled chambers.
• Trace elements: Specialist equipment often detects nitrogen in natural stones; lab-grown typically show no nitrogen, aiding identification.
• Growth features: Rough crystals show different growth patterns (CVD vs HPHT vs natural); once cut, only a lab can tell.
• Price: Lab-grown generally retail significantly lower than natural, for like-for-like grades.

These differences affect identification and budgeting, not everyday wear or beauty.

Can you tell lab-grown from natural? Testing and identification

To the naked eye—and even under a loupe—no. Cut lab-grown and natural diamonds look and behave the same, and both pass standard diamond testers because they are diamonds. Distinguishing origin requires specialist laboratory equipment that detects subtle growth features or trace elements. As UK experts note, labs often look for nitrogen: natural diamonds typically contain tiny amounts; lab-grown usually don’t. In their rough state HPHT, CVD and natural crystals show different growth shapes, but once cut and polished, definitive identification is a lab job.

• Check the certificate: Reputable stones come with a report stating origin (lab-grown or natural).
• Read the laser inscription: GIA/IGI inscribe a unique report number on the girdle; IGI also adds “lab grown”.
• Ask how it was screened: Serious jewellers use advanced screening and submit stones to independent labs when needed.

These steps confirm what your eyes can’t—origin—without compromising on the beauty or durability you see and feel every day.

Lab diamonds vs moissanite and cubic zirconia

If you’re weighing up what are lab diamonds against popular look‑alikes, remember this: lab diamonds are real diamonds, while moissanite and cubic zirconia are simulants with different chemistry and behaviour. They can appear similar at a glance, but their sparkle, durability and long‑term look are not the same.

• Composition: Lab diamond = pure carbon; moissanite = silicon carbide; cubic zirconia (CZ) = zirconium dioxide.
• Sparkle: Diamonds show a crisp, mostly colourless scintillation; moissanite’s higher refractive index gives a vivid, rainbow “fire”; CZ often looks glassier and less lively.
• Hardness & wear: Diamond is Mohs 10; moissanite is slightly softer but very durable; CZ scratches more easily and can look tired or yellow with wear.
• Optics: Moissanite can display a subtle yellow/green tint and double refraction that may look hazy at larger sizes; diamonds remain sharp and bright.
• Price: Moissanite and CZ are significantly cheaper than diamonds; lab diamonds cost more than simulants but far less than equivalent natural diamonds.
• Grading: Lab diamonds are graded and certified as diamonds (e.g., GIA/IGI); simulants are not diamond‑certified.

Choose lab diamond for authentic diamond beauty and grading; moissanite for bold rainbow sparkle on a tighter budget; CZ for fashion‑level cost.

How much do lab diamonds cost in the UK?

Lab-grown diamonds in the UK typically retail 60–85% less than natural diamonds of the same grades. That saving is clear at popular sizes: a well-cut 1.00ct lab diamond in top white colour and VS clarity often lists around a few thousand pounds, where an equivalent natural diamond is many thousands more. The gap lets you step up in carat or quality for the same budget.

Prices vary with the 4Cs and market availability. To compare fairly, match specifications like-for-like.

• Cut first: The biggest driver of beauty and price.
• Colour and clarity: Higher grades cost more; balance for value.
• Carat weight: Small jumps near 0.50ct, 1.00ct, 1.50ct, 2.00ct affect price.
• Shape: Round usually costs more than fancy shapes (oval, emerald, pear).

Ask for certified stones in your target specs and compare side-by-side quotes.

Value and resale: what to expect over time

Set expectations early: the future value of lab-grown diamonds is uncertain, and like natural diamonds, the resale price is typically lower than what you originally paid. The main reason lab diamonds cost less at retail is production efficiency, not inferior quality—so treat them as a luxury to enjoy, rather than an investment to flip.

Resale outcomes depend on market demand and documentation. Because only specialist equipment can determine origin, your grading report and laser inscription matter when you come to sell or upgrade. Practically, choose a stone you’ll love wearing for years and consider the savings a way to maximise size or quality within your budget.

• Keep paperwork: Secure GIA or IGI reports and note the laser inscription number.
• Prioritise cut: Beauty helps long-term desirability more than marginal colour/clarity jumps.
• Choose balanced specs: Opt for well-proportioned 4Cs that are broadly appealing.
• Maintain condition: Regular cleaning and servicing support future saleability.
• Ask policies: Check your jeweller’s upgrade or part‑exchange options before buying.

Quality and the 4Cs: how to choose a great lab diamond

If you want that instant “wow” when the box opens, start with the 4Cs. Lab-grown diamonds are graded just like natural ones, so the same quality rules apply. The smartest buys put beauty first, not just headline specs: focus on cut for sparkle, then balance colour, clarity and carat to suit your budget and style.

• Cut (priority one): Choose Excellent cut for round diamonds; for fancy shapes, look for Excellent polish and symmetry. A superb cut maximises brightness and fire and will outshine higher colour or clarity with a weaker cut.
• Colour: Aim for bright, white stones. Many UK experts suggest D–F for a crisp look, especially in platinum/white gold. Warmer metals can pair beautifully with near‑colourless grades if you prefer.
• Clarity: Pick “eye‑clean” stones where inclusions aren’t visible without magnification. VS2 to SI1 often offers excellent value while remaining clean to the naked eye in most shapes.
• Carat: Size affects presence and price. Once cut, colour and clarity are where you want them, choose the carat that delivers the look you love on your hand.

Always confirm your choice with an independent grading report and a matching laser inscription for peace of mind—next, we’ll explain GIA vs IGI and what to look for on a certificate.

Certification and grading: GIA vs IGI, reports and inscriptions

Independent certification is your proof of what you’re buying. The two most recognised labs for lab-grown diamonds are GIA and IGI. Both grade lab diamonds against established standards and confirm origin. As UK jewellers note, IGI uses the familiar letter/number grades (e.g., D colour, VS2 clarity), while GIA grades lab diamonds and notes their laboratory origin and growth method (CVD or HPHT). Both inscribe a unique report number on the diamond’s girdle; IGI also adds “lab grown”. The inscription is viewable under magnification (around 50x) and should match the report.

• Confirm origin: The report must clearly state “laboratory‑grown diamond”.
• Match numbers: The laser inscription on the girdle must match the certificate number.
• Check the grader: Prefer GIA or IGI for consistency and global recognition.
• Verify the 4Cs: Ensure the cut, colour, clarity and carat align with what’s been quoted.
• Look for growth info: Many reports note CVD or HPHT; keep this with your records.
• Review finish grades: Polish and symmetry help you judge make quality.

Keep the certificate and inscription number safe—they’re essential for insurance, upgrades and future verification.

Ethics and sustainability: conflict-free, traceability and energy

For many, the appeal of lab-grown diamonds is ethical as much as aesthetic. Growing a diamond above ground removes large-scale excavation and greatly reduces the risk of conflict financing, but “more ethical” isn’t automatic. The true footprint depends on traceability and the energy used to grow the stone, so it pays to ask the right questions.

• Conflict risk: Lab diamonds are inherently conflict‑free. For natural stones, the UN’s Kimberley Process makes buying a “blood diamond” near impossible when you choose reputable jewellers.
• Traceability: Ask for documented origin and growth method (CVD or HPHT) and ensure the certificate states “laboratory‑grown”. Some retailers offer full, transparent supply chains.
• Land and biodiversity: Lab growth uses far less land than mining, avoiding excavation and habitat disruption.
• Energy and carbon: Energy use varies widely. Industry commentary has suggested figures around 250 kWh per diamond, while some producers claim as little as 20 kWh thanks to efficiency gains. Preference should be given to labs using renewable energy or with credible carbon‑reduction measures.
• Social impact: Ethically run mines can support livelihoods in mining‑dependent regions; meanwhile, most diamond labs operate in developed countries. Weigh what matters most to you: reduced land use and conflict risk, or supporting responsible mining communities.

A balanced ethical choice comes from transparent origin, reputable certification and clear energy disclosures alongside the craftsmanship you value.

Shapes, sizes and colours: what’s available with lab diamonds

Lab-grown diamonds are available in the same breadth of shapes and size ranges as natural stones. Round remains the classic choice, while fancy shapes are widely offered and can provide extra spread for your budget. Because lab diamonds typically cost less than mined, many buyers step up in carat weight without compromising on cut or colour. In terms of colour, you can choose bright, colourless stones (e.g., D–F) or explore fancy colours created by controlled trace elements—an option that includes yellow, blue, pink, orange, green, red and black, as industry guides note.

• Shapes: Round plus popular fancy shapes such as oval, emerald and pear.
• Sizes: From delicate accents to statement centre stones, with more carat for the same spend.
• Colours: Classic colourless and an array of fancy hues grown consistently in the lab.

Settings and ring design: pairing lab diamonds with your style

Start with how you’ll wear your ring day‑to‑day. The setting frames your lab diamond’s sparkle and dictates comfort, security and style. Because lab‑grown often frees budget, you can elevate the design without sacrificing the stone. Choose a setting that suits your lifestyle and the shape you love.

• Solitaire: timeless and versatile; maximises light return.
• Halo/hidden halo: bigger look with subtle or showy sparkle.
• Trilogy: meaningful three‑stone; balanced finger coverage.
• Bezel: sleek and protective; great for active wearers.
• Pavé/diamond band: extra shimmer; plan a flush‑fit with wedding band.
• Cathedral vs low‑set: height and drama vs snag‑resistant comfort.

Match metal to mood: platinum/white gold for crispness; yellow or rose for warmth and contrast.

Care and maintenance: durability, cleaning and servicing

Lab-grown diamonds are as durable as natural diamonds (Mohs 10), but “hard” isn’t “indestructible”. Daily wear can loosen prongs, collect oils and soap film, and sharp knocks can chip exposed edges. A simple routine keeps your ring bright and secure, and periodic professional checks protect your setting for the long term.

• Clean weekly: Warm water + a drop of mild washing‑up liquid, soft brush under the stone, rinse, pat dry with a lint‑free cloth.
• Avoid harsh chemicals: No bleach, chlorine or abrasive cleaners; remove for the gym, gardening and swimming.
• Ultrasonic/steam: Often safe for diamonds, but avoid with delicate settings or significant inclusions—ask your jeweller first.
• Check and service: Have claws, settings and band wear inspected every 6–12 months; tighten stones, re‑polish and re‑rhodium as needed.
• Store smart: Keep separately in a soft pouch or lined box—diamonds can scratch other jewellery.
• After a knock: If you catch the ring, stop wearing it and book an inspection.

A Star Diamonds clients can use our lifetime cleaning, polishing and resizing to keep UK‑made pieces looking and wearing their best.

Buying tips: questions to ask and common pitfalls

Buying a lab-grown diamond should feel exciting, not daunting. A simple checklist turns glossy descriptions into hard facts and helps you compare like‑for‑like. Ask these questions, get the answers in writing, and you’ll avoid surprises on price, quality and aftercare.

• Is it certified? Ask for a GIA or IGI report that clearly states “laboratory‑grown”.
• Does the inscription match? Confirm the laser‑inscribed number on the girdle matches the certificate; IGI also inscribes “lab grown”.
• How was it made? Request the growth method (CVD or HPHT) and whether any post‑growth treatments are disclosed on the report.
• How good is the cut? For rounds, look for Excellent cut; for fancy shapes, Excellent polish and symmetry.
• Is it eye‑clean? Get clarity performance confirmed and know your return/exchange window.
• Are we comparing like‑for‑like? Match 4Cs, fluorescence notes and measurements before comparing prices.
• What about aftercare? Clarify resizing, lifetime cleaning/polishing, prong checks and where the work is carried out.
• Ethics & energy: Ask about origin traceability and any renewable‑energy claims.
• Logistics: Confirm lead time, insurance valuation, and any upgrade or part‑exchange policy.

Common pitfalls

• Chasing carat over cut: Size without sparkle disappoints; prioritise cut quality.
• Mixing specs in comparisons: Tiny changes in 4Cs or shape skew price.
• Buying uncertified stones: No independent report, no deal.
• Overlooking practicality: Setting height, wedding band fit and metal choice affect daily wear.
• Skipping maintenance: Budget time for periodic checks to keep stones secure and sparkling.

Why choose A Star Diamonds for a lab-grown diamond ring

Your engagement ring should feel personal from the first sketch to the final polish. As a family‑run Hatton Garden jeweller, A Star Diamonds blends gemmological expertise with in‑house craftsmanship to create UK‑made lab‑grown diamond rings that reflect your story, your ethics and your budget—without compromising on brilliance or build quality.

• Bespoke design, guided: One‑to‑one support from our goldsmiths, designers and gemmologists.
• Certified and traceable: GIA/IGI‑graded, laser‑inscribed lab diamonds; 100% conflict‑free.
• Made in Hatton Garden: UK craftsmanship, meticulous setting and finishing in‑house.
• Lifetime aftercare: Free resizing, polishing and cleaning, plus complimentary engraving.
• Smarter 4Cs choices: Clear advice to maximise sparkle and value for your spend.
• Flexible consultations: In‑person or virtual appointments, with phone/WhatsApp support throughout.

If you’re comparing lab‑grown and natural, we offer both—ethically sourced and transparently presented—so you can choose with confidence.

Key takeaways

Lab-grown diamonds are real diamonds, created with HPHT or CVD and graded like mined stones. They match natural diamonds in look and wear, differ mainly in origin and price, and need specialist tools to identify. Choose with the 4Cs, trusted certification and clear aftercare, guided by your ethics and budget.

• Real diamond, not a simulant.
• Same performance; significantly lower price than mined.
• Certification matters: GIA or IGI with matching inscription.
• Resale is uncertain; buy for love, not investment.
• Ask about growth method, energy use, traceability and aftercare.

Ready to compare stones or design a ring? Speak with the team at A Star Diamonds for expert, UK-made craftsmanship and transparent advice.