Hallmark Loupe
Also: Jeweller's loupe, Goldsmith's loupe, Loupe
A magnifier, typically with 10x to 30x magnification, used to inspect fineness stamps, hallmarks and striking features on precious-metal coins and bars.
The hallmark loupe is the simplest and cheapest aid for the optical authenticity testing of precious metals. It makes it possible to render fineness stamps and hallmarks on coins, bars and jewellery legible to the naked eye and to examine them for signs of counterfeiting.
Magnification and designs
For precious-metal testing, 10x magnification (10×) has become the standard - the same scale that gemmologists and jewellers worldwide use for stone grading. Stronger loupes (20× to 30×) are suited to the finest striking details but require a steady hand and good light.
| Type | Magnification | Typical use |
|---|---|---|
| Pocket loupe | 5× - 10× | Reading hallmarks, rough inspection |
| Jeweller's loupe | 10× | Standard authenticity test |
| Stand loupe / linen tester | 10× - 20× | Striking details, edge lettering |
| Microscope loupe | 20× - 30× | Finest structure inspection |
What the loupe reveals
With the hallmark loupe the following features can be assessed:
- Fineness stamps - e.g. "585", "750" or "999" on gold and silver; on genuine pieces the digits are sharp and evenly struck.
- Mint marks and mint stamps - logo details such as the kangaroo of the Perth Mint or the maple-leaf strike of the Maple Leaf are razor-sharp on originals.
- Edge lettering and security features - many bullion coins carry a circumferential edge inscription or reeding, which on counterfeits is often blurred or faulty.
- Surface texture - counterfeits often consist of a base carrier material (e.g. tungsten) with a thin gold coating; the loupe can reveal transitions, bubbles or casting seams that an original does not show.
Limits of the method
The hallmark loupe is a first visual inspection, not proof. High-quality counterfeits with a correct stamp and a similar surface appearance are not reliably detected with it. Supplementary methods such as the coin weight check, the coin size check and the authenticity check reveal deviations that remain optically invisible. For high-value goods, an X-ray fluorescence analysis (XRF) at a specialist dealer is recommended.
In brief
The hallmark loupe costs a few euros but immediately delivers usable indications of faulty stamps, poor striking or visible signs of counterfeiting - making it the sensible first step of any precious-metal authenticity test.