A Tarnished Rolex

Luxury watches are typically crafted with precious metals for the case. However, since gold is relatively soft, traditional methods use 18-karat gold to ensure durability.

This alloy consists of 75% gold and 25% other metals such as silver, copper, and rhodium. While gold itself is highly stable, metals like copper and silver can oxidize over time, leading to tarnishing—commonly known as ‘gold rust.’ This is not a defect; the discoloration can easily be wiped away with a cloth.

At times, this oxidation produces stunning, rainbow-like patterns. Such tarnish usually occurs on watches that have been stored for long periods. Regular use reduces oxidation due to friction, so collectors often regard these natural patina marks as indicators of a case’s original condition and may intentionally preserve them.