1. Jewelry Identifier
  2. Hallmarks
  3. PURPLE GOLD

* gold-alloy-modifier hallmark

The PURPLE GOLD hallmark: meaning, purity & value

Purple gold (Au-Al intermetallic compound AuAl2). 79% gold by mass approximately equivalent to 18K. Extremely brittle (cannot be cast as a structural ring), used as inlay or accent stones.

Published May 30, 2026

Quick facts

Metal
gold-alloy-modifier
Purity
75.0%
Fineness
750/1000
Common regions
international

Stamps that mean the same thing

This purity may be struck into jewelry as any of: PURPLE GOLD / AMETHYST GOLD / AuAl2. The mark differs by country and era, but the metal content is identical.

What PURPLE GOLD tells you

Purple gold (Au-Al intermetallic compound AuAl2). 79% gold by mass approximately equivalent to 18K. Extremely brittle (cannot be cast as a structural ring), used as inlay or accent stones.

How to check it yourself

  1. Examine the stamp under a 10× loupe — genuine marks are crisp and evenly struck, not doubled or smeared.
  2. Confirm the mark reads PURPLE GOLD or an equivalent such as AMETHYST GOLD.
  3. Photograph it in the Jewelry Identifier app to read the metal, hallmark, and any gemstones from the image.
  4. For a binding result, have an assay office or gemological lab run an XRF purity test.

* Frequently asked

FAQ

Q. Is PURPLE GOLD the same as AMETHYST GOLD?
A. Yes. PURPLE GOLD, AMETHYST GOLD, AuAl2 all denote the same material — 75.0% gold-alloy-modifier. Different markets and eras stamp it differently, but the purity is identical.
Q. How do I confirm a PURPLE GOLD stamp is genuine?
A. Look at the mark under 10× magnification for crisp, even strikes, cross-check the weight-to-volume ratio against the expected density, scan it with the Jewelry Identifier app, and — when it matters — have an XRF test done by an assay office or gemological lab.

* Try it

Identify the jewelry in your hand, right now.

Just take a photo — AI reads the metal, gemstone, hallmark, era, and an estimated value range in seconds. First two scans free, no account required.

Download on the App Store

* Related

Keep exploring