Skip to content

Hallmark field guide

What Does 375 Mean on Jewelry?

In a genuine precious-metal marking system, 375 is a gold fineness claim of 375 parts gold per 1,000 parts alloy. It is a recognized 9-karat standard in the UK. Read the complete mark and the object together before drawing a conclusion.

Updated August 5, 2026Sources listed on page

The remaining alloy can contain metals selected for color, hardness, and manufacturing properties.

Under the UK system, the number should be read with the sponsor or maker mark and assay-office mark—not as a complete hallmark by itself.

Common interpretation

37.5% gold; commonly described as 9 karat

Material category

Gold alloy

What the mark can suggest

In a genuine precious-metal marking system, 375 is a gold fineness claim of 375 parts gold per 1,000 parts alloy. It is a recognized 9-karat standard in the UK.

What it does not prove

  • That the stamp is genuine
  • The maker, date, country, or market value
  • That every component has the same alloy

What to check next

  1. 1Photograph the entire mark set
  2. 2Look for sponsor, assay-office, date, plating, or import context
  3. 3Use metal testing when a financial decision depends on the result

Frequently asked questions

Is 375 real gold?

375 is a claim that the alloy is 37.5% gold. Whether a particular item meets that claim requires context and, when needed, testing.

Is 375 the same as 9K?

It is the recognized 9-karat gold fineness in the UK hallmarking system.

Sources and further reading

This guide summarizes the official and institutional references below. Open the original source for its full scope, jurisdiction, definitions, and updates.

  1. UK Government

    Hallmarking is the law: guidance summary

    Explains compulsory elements of a UK hallmark and how fineness is expressed in parts per thousand.

    https://www.gov.uk/government/publications/hallmarking-guidance-notes/hallmarking-is-the-law-guidance-summary

  2. UK Government / British Hallmarking Council

    Hallmarking: fineness guidance

    Official reference for recognized UK precious-metal fineness standards.

    https://www.gov.uk/government/publications/hallmarking-fineness-guidance

  3. U.S. Federal Trade Commission

    Buying Platinum, Gold, and Silver Jewelry

    Consumer guidance on karat marks, silver fineness, plating, filled products, and maker marks.

    https://consumer.ftc.gov/articles/buying-platinum-gold-and-silver-jewelry

Continue your research

417 jewelry mark41.7% gold; commonly described as 10 karat585 jewelry mark58.5% gold; commonly described as 14 karat750 jewelry mark75.0% gold; commonly described as 18 karatBrowse metal and hallmark guidesLearn how fineness, maker, assay, plating, and construction clues fit together.

Start with a structured photo screen

Capture the whole piece, every mark, construction details, and condition. The photo tool will organize visible clues and tell you where uncertainty remains.

Scan a jewelry photo