It sounds a lot less regal when you call them short tailed weasels.
Or indeed stoats
It’s the mink’s water-loving habits and semi-aquatic lifestyle that’s responsible for that luscious fur.
Ferrets are domesticated weasels, and I would not call their pelt luxurious. I had three of them, including a white one with a black tail tip that made her look like a ermine year-round.
Apparently there is a fur trade for their wild ancestors, though certainly not the most expensive one.
The other heraldic fur is vair, which represented a cloak lining made of squirrel fur.
Technically, sable (heraldic black) is also a fur, although it isn’t used the same way in heraldry. But it is named for sable fur.
Info on the sable, since I went and looked it up anyway:
Fascinating info about their usage.