I've not made many brooches and the ones I have, have been in copper. I don't even wear brooches that often, although I do find them rather beautiful - and it's a rare type of jewellery that sits on clothing rather than the body.
The brooch that I do wear with any regularity is a gift I received several years ago, an amethyst set in silver. I've worn it on a hat for years now, and it's stayed firm, never coming loose. This summer, when I decided to wash the hat, I naturally removed the brooch. That was fine. When my hat was dry and I went to reattach the brooch... it broke.
Breaking jewellery is not a nice feeling. The pin at the back came away from the main part of the brooch and as I looked down at the two pieces I immediately assumed something had disastrously snapped, delicate and difficult soldering would be needed, I wouldn't be able to protect the amethyst and, essentially, it was game over for my brooch.
When I looked a little closer I saw that the pin, which I'd never thought to examine before, had simply pulled free from the pressure setting it was normally enclosed within. Five minutes with a pair of pliers and the brooch was fixed and I was suitably pleased.
Photographic proof above. Including wonderfully-aged tarnish on the back of the brooch...