Further to my unforgivable boo-boo. This article provides a pretty good introduction to the subject and there's a diagram of a quartz crystal at the beginning indicating the position of AT cuts in relation to the crystal and other cuts.

I've seen much more detailed diagrams of the crystal and cuts/cutting angles but I can't find one online. . Those precision diagrams are required by those who cut the quartz at the start of the manufacturing process.

https://xoprof.com/2023/09/unleashing-the-mystery-of-crystal...