The ever lasting diamond stylus...is it a myth or??


We all believe that a stylus has a certain life...perhaps on the order of several thousand hours. However, it occurs to me that if a stylus is used exclusively on new and/or pristine and clean vinyl and that the various parameters of set up are always maintained correctly; that it would/could be reasonable to expect the diamond to last almost indefinitely! The wear and tear of the groove against the diamond, particularly if the friction on the stone is minimized should allow an immense life. The other components of the cartridge can- and will, age far before the diamond shape is lost....due to the aging of the rubber and other soft components in the motor...BUT the diamond....I think perhaps not....thoughts???
128x128daveyf
One side of one average album is ~one mile distance.

According to the Wikipedia article about the LP record, 
The average LP has about 1,500 feet (460 m or about a third of a mile) of groove on each side.
So both sides of a record combine to make about 2/3 of a mile of grooviness.

I'd read that 1400-1500' figure other places as well.
Phono diamonds are man made, not the natural ones you find in most engagement rings.....  not nearly the same quality.  If indeed they are man made, can they really be called diamond...or diamond-like.
I can't tell if a diamond is worn using a 20X loupe. I was thinking of getting a 5 MP, 20-300X digital scope; but a totally gonzo cartridge/stylus photographer and re-builder on another forum posted that you need a combination of microscope and camera optics to get sufficient depth of field to see wear.

For $50 bucks, I may still try it if I get a new stylus for my MM. Then I'd compare old and new and see if I waited too long or long enough. Since the process is soooo gradual; I don't trust my aging ears.

I will say that I have a Shure V15RS with the original HE stylus from 20 years ago. I bought 2 new JICO styli, a SAS and an xMR. The HE and MR sound somewhat comparable, with the HE being stronger on the low end and the MR on the high end. Shape or wear??? I dunno; but I use the HE on older LPs with more surface noise. It is more forgiving and I figure the damage is done already.