Journal

Gold Lab

Hands-on tutorials and how-tos: reading hallmarks, testing purity, valuing inherited pieces, spotting fakes.

Most questions about a piece of gold can be answered before anyone gets near a testing kit, because the marks are usually already there. A British hallmark has three compulsory parts — a sponsor's mark identifying who submitted the article, a millesimal fineness mark giving the gold content in parts per thousand, and an assay office mark showing where it was tested. Read together they tell you who, how pure, and verified by whom. What matters when you are looking at an unfamiliar piece is that countries do not all work this way. Some operate independent assay offices that test before an item can be sold as gold; others regulate the accuracy of the maker's own marking and leave the testing to the trade. A mark is therefore evidence of a system as much as of a metal, and knowing which system you are reading is the first step in valuing anything inherited or bought secondhand.