The biggest issue here is the reliability of the makers claims !!
However gold plating is a process of depositing a thin layer of gold onto the surface of another metal by either chemical or electro-chemical plating. It is generally used on low cost jewellery, because it is inexpensive and easy to apply. The problem with gold plating is it lacks durability and can discolor within a short period of time, if the jewelery is subject to only normal wear. Most cheap imported gold plated jewelery is only one micron thick, which gives it a very limited lifespan. Makers generally claim 5 microns on thier better models..
DLC is applied using a PVD process as i mentioned a while ago comparing PVD and DLC is like comparing paint and brush. DLC is generally harder, hardness is measured in Vickers and can vary from several hundred Vickers upto 5000 Vickers, that being the hardest I know of in a gen watch finish...though that hardness of 5000 requires another reaction to be undertaken during the PVD application of the DLC.
PVD plating stands for “physical vapor depositionâ€, because gold is vaporized in a vacuum chamber and deposited on the intended piece of jewelry. When PVD is used with titanium nitride, a very hard material it provides an extremely durable coating of gold, which is the reason it is used in medium to higher priced jewelry – especially watches. Additionally, it is more resistant to corrosion by sea water and sweat than gold plating.
The titanium nitride is first applied to the piece, which produces a very hard rough surface. When the gold is applied, it first fills the minute cavities in the rough surface and builds up to form a smooth surface. Since the high points of the titanium nitride are so hard, they protect the jewelry so the gold doesn’t wear away as fast. A typical application of PVD gold plating that is applied to watches is 10 microns, or at least 10 times the thickness of typical gold plating and many times more durable than the thickness implies.
PVD plating with titanium nitride is not scratch proof, but it takes a bit of effort to scratch through to the base metal. It is a more complicated process to apply and requires expensive capital equipment, which makes it a more expensive addition to jewelry.
So although DLC gold applied using PVD is without question harder than gold plating...the key thing to know is
1) Is the DLC applied using titanium nitride or similar?
As we know there are makers using factories to produce these parts who also make items for proper/genuine brands so it is not beyond the realm of possibilty that these claims are more than possible... I tend to think it more likely than not in certain models like the RG JPM as I have held one in my hand..
I do know from some reliable info by guys that do know is that the DLC process is used by the makers on these models what I dont know is if they use titanium Nitride... that tech detail is beyond thier ability to garner..
But bottom line is that this gold application is harder and more long wearing than the traditional makers process of plating...afterall it is by definition...
but how much harder is difficult to say...
Happy New Year to you too my friend 