What does “PT” mean?

PT is the standard abbreviation for platinum, taken from its chemical symbol. Platinum is used for some of the most expensive references from high-end brands. Watch platinum is usually 950, meaning 95 per cent pure, and it is noticeably heavier than gold or steel.

Platinum can look a lot like white gold or steel in photos, so it is worth knowing the clues. Some brands mark platinum models in specific ways: Patek Philippe traditionally sets a small diamond in the case of its platinum watches, and Rolex often pairs platinum with an ice-blue dial on models such as the Day-Date and Daytona. Hallmarks on the case and the reference number are the most reliable way to confirm the metal. Platinum also scratches and polishes differently from gold, developing a soft, slightly matte surface with wear.

A typical listing line: “Rolex Day-Date 40, 228206, PT, ice-blue dial, 2021 card, full set.” On modern Rolex references the final digit 6 indicates platinum.