PURIX
Gold, karat and measurement.
Useful knowledge for the jeweller’s counter: short, sourced, new every week.
How do you read a gold test result? Karat, fineness and element percentages
At the end of an XRF measurement, the screen shows the karat, the fineness and the element percentages. We explain, with sources, how these three figures follow from each other, what the other metals tell you and what to do when the result does not match the stamp.
October 29, 2026 · 5 min readRead the articleHow do you convert karat to fineness? Conversion table from 8 to 24 karat
Karat and fineness are two ways of writing the gold ratio: one out of 24, the other out of 1,000. In this article we explain the two-way conversion formula, give the full table from 8 to 24 karat, and show why the number in the stamp can differ slightly from the calculation.
October 26, 2026 · 5 min read
How do you verify the karat when buying scrap gold?
Scrap gold brings together pieces from different years, different workshops and different karats. The stamp is a starting point, but it is not enough on its own. We explain, with sources, the steps to follow at the jeweller’s bench to verify the karat of a scrap piece.
October 25, 2026 · 5 min readHow can you tell plated gold?
Plated gold is a piece with a thin layer of gold applied to the surface of another metal. From the outside it is hard to tell apart from solid gold. We explain the types of plating, the marks in the stamp and the steps to follow at the jeweller's counter, with sources.
October 20, 2026 · 5 min readHow does XRF gold analysis work?
XRF (X-ray fluorescence) is an analysis method that measures the elements in a piece and their proportions without damaging it. In this article we explain, in plain language, the physics of the method, how the result is calculated and the limits a jeweller should know.
October 14, 2026 · 5 min readHow is gold karat measured? Touchstone, acid test and XRF
Karat tells you how many parts out of 24 of an alloy are pure gold. Jewellers commonly measure this ratio in three ways: the touchstone, the acid test and XRF analysis. We compared all three side by side on the same criteria.
October 11, 2026 · 4 min read