Lost stylus seeking similar experience

Yes, two things Elliott mentioned above are pertinent and perhaps prescient.  LAST does make a stylus cleaning liquid.  It is powerful stuff and there is no doubt in my mind that regular use could degrade adhesive.  I have a bottle here in Florida, but rarely use it.  Most importantly it had never been used on my AT ART20.  Inadvertent fumble fingers or some such is by far the most likely root cause of my missing diamond.  I don’t know how I did it, but the cartridge was untouched by any other human since I acquired it.  I believe mishandling is the answer to the mystery. 

@billstevenson 

I really think its just a matter of trying to bond dissimilar materials together using an adhesive. I would never trust a stylus stuck out the end of a boron cantilever with a glob of glue, like I see on so many cartridges’ these days even though your ART20 uses a more elaborate method AT claims that is supposed to reduce moving mass as well as improve the bond. Maybe at least one design objective was achieved.

For Stylast to work you are instructed to use their record treatment also. It is supposed to change the surface of a record in a manner, I forget exactly how since it has been awhile since I looked at it. I do remember one person on Audiokarma who used Stylast religiously but not the record treatment. After a 1000 hours he had the diamond inspected on his cartridge and it was worn out as a typical diamond would be. He was crestfallen. 

As I recall, there are some MDS out on the Stylast products that will give you the chemical composition, but not the percentages.

I have lost diamonds two times off cantilevers. Once I suspect because I had a cue mishap and set it down too hard. I think I may have weakened the bond. The second one was no mishap, it just detached in mid play. 

I ended up changing how I apply my stylus cleaner. Before I had brushed directly onto the diamond, and then used the brush. These days I apply the fluid onto the brush a bit enthusiastically, and then use the wetted brush to clean the diamond. No issues with this technique.  

With a magnifying mirror under the cartridge, and decent amount of reflected light, you can see which ones have a blob of glue, and which ones are into a laser cut hole in the cantilever, any speck of glue would be on top, out of sight, not the bottom. I occasionally use stylus cleaner on them, not the ones with visible blobs.

Faustuss, thank you for reminding me/us that LAST did make two different products, one for cleaning and the other was Stylast, for lubricating the stylus. I am embarrassed because I used to own both and probably still do have them stashed away somewhere.  I stopped using them probably 20 years ago, but the product I used most was the cleaner, not Stylast.  As I recall, the bottles were numbered, maybe "4" and "5", respectively.  All of that said, I still do not think either product could have contained any solvent capable of eating epoxy bonds, if for no other reason than the given longevity of the solutions as described by LAST.  Anything that can affect epoxy would be volatile and probably would contain acetone or a derivative. Acetone has a distinct odor, and both solutions were odorless, as I recall. And acetone would evaporate off after a few weeks or months. Plus, epoxy adhesives were strong enough to bond ceramic tiles to the space shuttle nose cone during re-entry.  I don't think there is any inherent fault with epoxy for glueing a stylus to a cantilever, per se. I am guessing that the occasional stylus is not properly glued to the cantilever in the first place, during manufacture, such that the trauma of repeated brushing might eventually loosen it.