One side of one average album is ~one mile distance. Yes, diamond is harder than vinyl, but if you have gunk in the grooves; like dust and dirt it will wear down (grind) the diamond over time. We are taking 3000 - 5,000 miles use. The record groove will also wear down. The first 'loss' you will notice is at the high end; treble. Don't forget the groove is shaped like a 'V' and at a specific angle. The sound waves are pressed along the side walls of the 'V' almost to the bottom. The diamond will travel along the sides of the 'V' until it hits bottom or the sound grooves are worn away. Good record cleaning and stylus cleaning procedures are mandatory!
You hit upon an important item. Many different diamond grinds exist for a stylus. One type may last longer than another, but one may capture the sound waves better than another. I do not know which shape is the 'best'.
My Lyra has a 'line contact' diamond. It is manufactured by a company in Japan that makes the pure Tungsten needles for scanning electron microscopes. I believe a company that can make devices for a SEM certainly could handle attaching a diamond to a single Pure Boron Whisker. It's been my experience (over 40 years) that I become bored of a cartridge prior to it ever wearing out.......
You hit upon an important item. Many different diamond grinds exist for a stylus. One type may last longer than another, but one may capture the sound waves better than another. I do not know which shape is the 'best'.
My Lyra has a 'line contact' diamond. It is manufactured by a company in Japan that makes the pure Tungsten needles for scanning electron microscopes. I believe a company that can make devices for a SEM certainly could handle attaching a diamond to a single Pure Boron Whisker. It's been my experience (over 40 years) that I become bored of a cartridge prior to it ever wearing out.......