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 15 September 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)
15.12ct OVAL E VVS2lab grown100£7,654 GBP
25.11ct HEART D IFlab grown100£10,123 GBP
35.06ct OVAL E IFlab grown100£10,024 GBP
45.04ct HEART E IFlab grown100£8,416 GBP
54.71ct HEART D IFlab grown100£6,790 GBP
64.56ct OVAL D VVS1lab grown100£8,700 GBP
74.24ct ROUND D VVS1lab grown100£3,470 GBP
84.22ct ROUND D VVS1lab grown100£3,127 GBP
94.21ct OVAL D VVS1lab grown100£4,973 GBP
104.16ct HEART D IFlab grown100£6,223 GBP
113.96ct OVAL D FLlab grown100£10,070 GBP
123.91ct OVAL E VS1lab grown100£979 GBP
133.79ct ASSCHER D FLlab grown100£9,616 GBP
143.67ct PRINCESS D VVS1lab grown100£3,084 GBP
153.62ct ASSCHER G VVS2lab grown100£1,648 GBP
163.60ct OVAL E VVS1lab grown100£5,839 GBP
173.57ct HEART D IFlab grown100£4,013 GBP
183.52ct OVAL E VS2lab grown100£4,928 GBP
193.51ct MARQUISE E VS2lab grown100£1,312 GBP
203.42ct ROUND E VVS1lab grown100£1,923 GBP
213.28ct ROUND F VS1lab grown100£527 GBP
223.28ct PRINCESS E VVS2lab grown100£5,521 GBP
233.26ct OVAL E IFlab grown100£3,350 GBP
243.17ct ROUND D VVS1lab grown100£734 GBP
253.09ct CUSHION D VVS2lab grown100£2,121 GBP
263.08ct OVAL G VS1lab grown100£1,625 GBP
273.07ct OVAL E VS2lab grown100£920 GBP
283.07ct OVAL G VS1lab grown100£1,556 GBP
293.05ct OVAL E VS2lab grown100£917 GBP
303.04ct ROUND D VVS1lab grown100£1,882 GBP
313.03ct OVAL D VVS1lab grown100£2,603 GBP
323.02ct EMERALD D VS1lab grown100£645 GBP
333.02ct OVAL E VS2lab grown100£1,535 GBP
343.02ct OVAL D VVS1lab grown100£2,594 GBP
353.02ct HEART D IFlab grown100£3,432 GBP
363.01ct ROUND F VS1lab grown100£484 GBP
373.01ct OVAL D VS1lab grown100£3,890 GBP
383.01ct ROUND D IFlab grown100£6,467 GBP
392.94ct OVAL E VS1lab grown100£1,512 GBP
402.92ct OVAL E VS1lab grown100£1,502 GBP
412.90ct HEART D VVS1lab grown100£1,583 GBP
422.84ct RADIANT E VS1lab grown100£704 GBP
432.80ct HEART D IFlab grown100£2,744 GBP
442.71ct OVAL F VS2lab grown100£2,342 GBP
452.70ct OVAL E VS2lab grown100£1,471 GBP
462.67ct ROUND D VVS1lab grown100£1,596 GBP
472.64ct OVAL D VVS1lab grown100£3,735 GBP
482.61ct OVAL D VS2lab grown100£1,010 GBP
492.58ct OVAL F VS1lab grown100£534 GBP
502.58ct RADIANT F VS1lab grown100£1,323 GBP
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