Hi Twocats,
Most of iron meteorites In the market will rust! There are a few quite stable ones!
Gibbeon from Namibia is one of them. Meteorite dealers told me the most stable pieces are cut out of the center of large lumps of the meteorites!
That are the most expensive pieces, as You can only use a small part of the big piece!
Additional, to get the Widmanstätten pattern visible, the meteorite pieces need to get etched by nitric acid.
If, after the etching the piece is not painstakingly neutralized and cleansed of all Rest of acids, also in all the pores and hairline cracks it will start to rust after a while. You can oil the pieces, or clear coat with lacquer, but if there is still acid in the piece, it will start again!
I do like meteorites, it’s an really interesting rare material, but you have to know most of them naturally rust, but a few!
But that’s also part of the beauty, though not on an watchcase!
Gibbeon Meteorite would have been a better choice, not the Swedish one!
https://en.m.wikipedia.org/wiki/Iron_meteorite
Greetings!