Top 50 Diamonds by Certification Score in United Kingdom

Ranked by certificate rigour. GIA and AGS stones with complete grading, clear symmetry, and verified provenance come out on top. Pricing shown in GBP.

Last updated 1 August 2026 · Based on 50 active listings ranked by certification

What Certification Score Rewards

Certification score measures the rigour and completeness of the grading report behind each diamond. It weights the grading lab (GIA and AGS lead; IGI and HRD follow; newer or less-consistent labs are lower), the presence of a polish and symmetry grade (required for Excellent-cut claims), and the completeness of the proportions data. It's not measuring the diamond itself. It's measuring how confident you can be that the grades on paper match what you'll receive.

Use this list when you're buying at a price point where certification rigour matters most. Say, above $10,000, or when the stone will be insured, resold, or given as a gift with a certificate presentation. The top of this list is where the paper trail is strongest: full GIA reports with polish and symmetry grades, complete measurement data, and a clean provenance.

A high certification score doesn't mean the stone is beautiful. It just means the grading is trustworthy. Cross-reference with quality score for stones that are both well-documented and well-made. For lab-grown, IGI tops this list more often than GIA because IGI has become the default lab-grown certifier and has the most complete reports for that segment.

#DiamondOriginScoreLowest Price (GBP)
16.06ct OVAL D VVS2lab grown100£11,665 GBP
25.12ct OVAL E VVS2lab grown100£8,164 GBP
35.11ct HEART D IFlab grown100£10,757 GBP
45.06ct OVAL E IFlab grown100£10,651 GBP
55.04ct HEART E IFlab grown100£8,943 GBP
64.71ct HEART D IFlab grown100£7,215 GBP
74.58ct ASSCHER E VVS2lab grown100£6,634 GBP
84.56ct OVAL D VVS1lab grown100£9,244 GBP
94.24ct ROUND D VVS1lab grown100£3,702 GBP
104.22ct ROUND D VVS1lab grown100£3,685 GBP
114.21ct OVAL D VVS1lab grown100£5,284 GBP
124.16ct HEART D IFlab grown100£6,613 GBP
134.09ct OVAL F VVS2lab grown100£4,441 GBP
144.07ct OVAL D VS1lab grown100£7,001 GBP
153.96ct OVAL D FLlab grown100£11,423 GBP
163.91ct OVAL E VS1lab grown100£1,391 GBP
173.79ct ASSCHER D FLlab grown100£11,226 GBP
183.67ct PRINCESS D VVS1lab grown100£3,277 GBP
193.62ct ASSCHER G VVS2lab grown100£543 GBP
203.60ct OVAL E VVS1lab grown100£6,205 GBP
213.57ct HEART D IFlab grown100£4,265 GBP
223.55ct ASSCHER F VS1lab grown100£4,413 GBP
233.52ct OVAL E VS2lab grown100£1,426 GBP
243.51ct CUSHION E VS2lab grown100£1,394 GBP
253.42ct ROUND E VVS1lab grown100£2,300 GBP
263.37ct PRINCESS E VS2lab grown100£3,992 GBP
273.37ct OVAL E VVS2lab grown100£5,039 GBP
283.28ct ROUND F VS1lab grown100£590 GBP
293.28ct PRINCESS E VVS2lab grown100£4,886 GBP
303.26ct OVAL E IFlab grown100£3,560 GBP
313.17ct ROUND D VVS1lab grown100£1,655 GBP
323.09ct CUSHION D VVS2lab grown100£2,882 GBP
333.07ct OVAL E VS2lab grown100£976 GBP
343.06ct ROUND E VS1lab grown100£11,398 GBP
353.06ct ROUND D VS2lab grown100£15,270 GBP
363.05ct OVAL E VS2lab grown100£672 GBP
373.04ct ROUND D VVS1lab grown100£2,135 GBP
383.04ct ROUND D VS2lab grown100£15,171 GBP
393.03ct ASSCHER E VVS1lab grown100£2,612 GBP
403.03ct OVAL D VVS1lab grown100£2,765 GBP
413.03ct ROUND E VS2lab grown100£13,587 GBP
423.02ct OVAL E VS2lab grown100£490 GBP
433.02ct EMERALD D VS1lab grown100£686 GBP
443.02ct OVAL D VVS1lab grown100£2,756 GBP
453.02ct HEART D IFlab grown100£3,646 GBP
463.01ct ROUND F VS1lab grown100£953 GBP
473.01ct OVAL D VS1lab grown100£1,889 GBP
483.01ct ROUND D IFlab grown100£6,606 GBP
493.00ct ROUND D VVS2lab grown100£4,657 GBP
502.94ct OVAL E VS1lab grown100£1,003 GBP
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