There is always easy to tell a Rolex is made of Gold (yellow gold or White gold) by their colour, how about can you tell if that is a watch of Platinum or White gold!?
From Left to Right, Ref 18038 Yellow Gold, Centre is White gold Day Date as it has 44 diamonds on the bezel, the one in the right is a Ref 1803 White gold, why we can tell if that is White gold not Platinum, becasue the rectangular diamond is shorther than those on Platinum.
This is no question stainless steel watch as this is Date Just , it does not come with Yellow Gold or Platinum.
But the Bezel is made of 18KT white Gold. Yes, there is Yellow gold Date just.
The one on the left is White Gold Day Date ref 18049 because there are 44 diamond on the bezel and the rectangular diamond is shorter than the one show below!
The one in the right is Stainless steel Date Just, (stainless steel only)
This is a Platinum Day Date Ref 18346 becasue there are 46 diamond on the bezel, and also the rectangular diamond at 6 O'clock is longer, can you notice? In Shorter, in later model like Ref 18346, the diamond is longer!
This is a classic , collector's dream watch Rolex Day Date Ref 1804, platinum as it has 46 diamond on the Bezel.
Rolex Ref 1804, Platinum 46 Diamonds
This is the fun part of Collecting Rolex as there are so many variations, different kind of dial, cases, and moreover a lot of knowledge for us to learn.
PS, I can not be right all the time as there are so many excetional, but here is base on what we learnt over the years.
Correct me if I am wrong!