This is our new series: Same or Different. Understanding Things by Comparing, as each Child Knows: Everything is Relative.

There is not much difference between a watch case made of steel or a case made of white gold or one made of platinum? Well, while all three don't appear like yellow gold, there are anyway some relevant differences:

• the density of stainless steel (8g per cubic cm) is approx half of 18K gold alloys (16g per cubic cm)
• the density of platinum is approx one third higher than of 18K gold alloys with 21g per cubic cm
• the Vickers hardness is up to 1'500 for special treated stainless steels but usually around 200 for a vintage watch
• platinum & 18K white gold is far less of around 120 - 150, depending on the used alloy
• the brightness of stainless steel that reflects approx 50% of the incoming light is much less than that of white gold and especially platinum
• the top pieces are rarely made of stainless steel, although you are told so by the watch making industry since the gold price took off in the 1970s and -- surprise -- the most "valuable" watches were since then made of steel;

So we have a different appearance and especially haptic experience with these three different metals -- and its easiest to see, when you have the same model in three different materials in front of you. And another aspect differentiates the gold or platinum examples from the steel watches: they are easier to scratch and get damaged much faster, what naturally reduces the number of these less-produced examples and furthermore they are brought to the smelter in thousands to extract the material value of the gold -- something that will never happen to a steel watch.

See the other parts in this series here: #SameOrDifferent