The 1V1 LONDON Guide to British Hallmarking & Diamond Standards

1. Why Hallmarking Matters (The Law)

In the UK, it is an offence to describe an item as gold, silver, platinum, or palladium unless it bears a recognised hallmark. A hallmark is your Consumer Protection—it is the only way to guarantee that the 18ct gold you paid for isn't actually brass.

2. The Weight Thresholds (When is a stamp required?)

Not every piece needs a hallmark. Small items fall under "Exemption Weights." If an item is below these weights, it does not legally require a hallmark:

• Gold: 1.0 gram

• Silver: 7.78 grams

• Platinum: 0.5 grams

• Palladium: 1.0 gram

The 1V1 Standard: Even if an item is under 1g (like some small studs), we often hallmark them anyway to maintain our engineering integrity.

3. Anatomy of a UK Hallmark (The 3 Compulsory Marks)

When you look at your 1V1 LONDON jewellery through a loupe, you will see three distinct stamps:

1. The Sponsor’s Mark: The unique mark of the company (ONE).

2. The Metal Fineness Mark: Tells you the purity.

◦ 375: 9ct Gold (37.5% pure gold)

◦ 750: 18ct Gold (75.0% pure gold)

◦ 950: Platinum (95.0% pure platinum)

3. The Assay Office Mark: Tells you where it was tested.

◦ Leopard's Head: London

◦ Castle: Edinburgh - I am registered with Edinburgh Assay Office. REF: 338064

◦ Anchor: Birmingham

◦ Rose: Sheffield

4. Diamond Clarity: From SI2 to FL

Clarity measures the "purity" of a diamond under 10x magnification.

• FL (Flawless): No internal or external flaws. The "Engineering Peak."

• VVS1–VVS2: Minute inclusions, nearly impossible for an expert to find.

• VS1–VS2: Very slight inclusions, invisible to the naked eye.

• SI1–SI2 (Slightly Included): Inclusions are visible under magnification and may be visible to a keen naked eye.

• I1–I3 (Included): Flaws are visible to the naked eye and affect the diamond's structural integrity.

The 1V1 Choice: We specialise in GIA-Certified diamonds, focusing on the VS range, where you get maximum "Performance" (shimmer) without paying the "Collector's Premium" of a Flawless stone.

Lee Barrett

Jewellery maker and designer.

https://1v1london.co.uk
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1V1 Essentials: The Architecture of the Daily Uniform