French, 18th century.
Measures 6 x 5.5 x 2.9cm excluding loose bail.
Weighs 254.8 grams.
A lodestone is a naturally occurring, magnetized mineral composed of magnetite (Fe₃O₄). It is unique because it exhibits natural magnetism, which allows it to attract iron and other ferromagnetic materials. Lodestones were used to re-magnetise compass needles, which gradually lost their magnetism over time and prevented the compass from functioning correctly.