Clogau Welsh Gold Technical Guide
This is a supporting guide to our main Clogau Brand Guide. It focuses on the technical aspects of Welsh gold — what a "trace" means, how it is verified, and the hallmarking system that guarantees authenticity.
Every piece of Clogau jewellery contains a trace of rare Welsh gold from the Clogau St David's mine. This inclusion is verified by the Edinburgh Assay Office through annual audits.
1 | What Is a "Trace" of Welsh Gold?
Each piece contains a consistent percentage of Welsh gold blended into the gold elements. Welsh gold is one of the rarest golds in the world — historically valued at up to 30 times standard market gold.
Where the Welsh Gold Sits
Rose Gold Pieces
Welsh gold is typically incorporated into the rose gold detailing — the warm-toned elements that contrast with the sterling silver base.
Platinum Pieces
An 18ct Welsh Rose Gold section is added specifically to include the rare metal, since platinum cannot be mixed with plain gold.
2 | Why Blending Makes Sense
The Clogau St David's mine closed in 1998. The available supply is restricted to stockpiles amassed during the late 1990s — a finite resource that cannot be replenished.
What Blending Achieves
- Longevity: The stockpile can sustain production for decades
- Accessibility: Pieces remain affordable rather than ultra-luxury only
- Consistency: Every customer receives the same Welsh gold inclusion
- Authenticity: The heritage value is preserved in every piece
3 | The Hallmarking System
Authentication Marks
| Mark | What It Confirms |
|---|---|
| Welsh Dragon | Welsh gold inclusion guaranteed |
| "CG" | Manufactured by Clogau |
| 375 | 9ct Gold — 37.5% pure gold |
| 750 | 18ct Gold — 75% pure gold |
| 925 | Sterling Silver — 92.5% pure silver |
| 950 | Platinum — 95% pure platinum |
| Assay Office mark | Independently tested and hallmarked |
Legal Thresholds
Silver: 7.78g
Hallmarking mandatory for silver items over this weight. Below this, Clogau conducts periodic voluntary testing.
Gold: 1g | Platinum: 0.5g
Mandatory hallmarking thresholds for gold and platinum items. All qualifying Clogau pieces meet these requirements.
4 | Edinburgh Assay Office Verification
Since 2004, Clogau has been registered with the Edinburgh Assay Office, which independently tests and marks every piece.
What the Assay Office Does
- Independent testing: Verifies metal purity on every piece
- Annual audits: Reviews Clogau's quality systems each year
- Certificate of assurance: Issues documentation confirming Welsh gold inclusion
- Chain of custody: Monitors the addition of Welsh gold to ensure consistency
Complete Audit Trail
This third-party verification provides a complete audit trail for the statement that Welsh gold is contained within each piece of Clogau jewellery. The combination of Welsh Dragon stamp, CG sponsor mark, and Assay Office hallmark confirms authenticity.
5 | Shop Clogau at OD's
Full Collection Available
Browse our full Clogau collection online, or visit us at 41 Barrow Street, St Helens to examine the hallmarks and craftsmanship in person.
Top Picks at OD's — In Stock Now
Three best-sellers our customers are choosing this month — all in stock, ready to ship from St Helens, available to try in our St Helens store before you buy.
All available in-store at 41 Barrow Street, St Helens, WA10 1RY — try before you buy.
Browse the full jewellery range at OD's.
6 | Frequently Asked Questions
What does a trace of Welsh gold mean?
Each piece contains a consistent percentage of Welsh gold blended into the gold elements. The exact percentage is a closely guarded family secret, but it remains consistent across every piece in the range.
How is Welsh gold inclusion verified?
The Edinburgh Assay Office independently tests and marks every piece. Annual audits review Clogau's quality systems and issue certificates of assurance confirming Welsh gold inclusion.
Why is Welsh gold blended rather than used pure?
The St David's mine closed in 1998. Blending ensures the finite stockpile can sustain production for decades while keeping pieces affordable and maintaining consistency for every customer.
What is the 7.78g rule?
UK law requires hallmarking for silver items weighing over 7.78 grams. Below this weight, Clogau operates a separate due diligence process involving periodic voluntary testing.