In the 1970s, a group of Swiss watchmakers who were part of the L’Association pour la Promotion Industrielle de l’Or or APIOR (which translates to The Association for the Industrial Promotion of Gold) formed an official initiative to highlight the use of gold on watches. APIOR wanted to formalize how watchmakers signified the use of precious gold in watches – especially important on steel watches since stainless steel and white gold are similar in color. The symbol chosen was the Greek letter Sigma: σ.
And here is a good example Rolex elegant ladies watch with a sigma dial. Look under marker six and you will see: σT-Swiss-Tσ. The Sigma symbol you see, it means that Rolex Sigma dials denote that the hand-applied indexes and hands are craft from 18k gold. So everything is gold what you see, goes up here!..;) The case and Jubilee bracelet have an elegant flow, it looks like a piece of jewelry. That is how a woman often wears here watch.( some men think that is not done, but women are different…::))
So if you wanna treat yourself or your loved one…this is a piece to consider!