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Not sure what is going on, but this is the second time in less than a week that I have found cracked jewels on an A6497-1. This is the only time I have come accross this problem, it's very rare except in old pocket watches that have been tinkered with by the unskilled. Both times the jewels were the top escape jewels (the one you see through the caseback), this one is only cracked through one side, the other was cracked completely accross in 2 pieces. Replacement is not straight forward, my Seitz Jewelling kit doesn't have the required 10/170 replacement jewel (10 is the size of the hole in 1/100mm and 170 is the diameter in 1/100mm). My sizes are 160 and then 180. So in order to install the 180 diameter jewel, the existing hole has to be broached to 0.179mm, the 0.001mm smaller diameter for the hole is what is needed to press fit the jewel and secure it to the escape c0ck. I am suspecting that something is happening during assembly, given that the pivot on the escape wheel is only 0.09mm in diameter, it's unlikely that it's causing the breakage, the pivot would fail before the jewel did. Most likely the installation of the jewel into the c0ck is where it's failing. Here's a picture of what I found today. Keep in mind that the jewel is sapphire, next harder substance is diamond. So if you have a cracked jewel, with a sharp edge made of sapphire, with a steel pivot turning in it and rubbing up against the sharp edge...guess what's going to happen and eventually fail. Hint...it won't be the jewel. All the more reason to never take for granted that all is ok, even on a new movement. Critical to inspect each and every part and component, you never know what you'll find...anyone else come accross this defect?