WHAT ARE THE TWO CIRCLES ON THE ROLEX DIAL/WHAT IS A SIGMA DIAL?

What exactly are those two circles on the bottom of my Rolex dial… These two circles, also known as ‘sigma’ signs highlight the use of gold on or throughout the dial of your watch. You can find ‘sigma’ dials across a range of different Rolex lines, they have been spotted on models such as the humble Oyster Perpetual all the way through to Daytonas, and it’s not just on Rolex watches. You can find ‘sigma’ dials on a range of brands from which include the likes of Omega and Patek Philippe. The ‘sigma’ signs were thought up as part of an initiative to highlight the use of gold in wristwatches by a group of Swiss watchmakers who were part of the APIOR (The association for the Industrial Promotion of Gold). Despite the sigma sign being officially adopted in the early 1970s, you can still find Rolex watches from the mid to late 1960s with the sigma sign as it was already in use by certain dial manufacturers. Here are a few examples of sigma watches we have had in the past.