With gathering professions now comes new passive and cast abilities. Mining now gives you the passive ability "Toughness". With each rank up in Mining, you obtain a new rank in this skill.

Here are the different ranks for this ability in order of ranks and Mining skill:
(mouse over the link to view the information for the rank)

75 - 149 (Apprentice):
Toughness (Rank 1)

150 - 224 (Journeyman):
Toughness (Rank 2)

225 - 299 (Expert):
Toughness (Rank 3)

300 - 374 (Artisan):
Toughness (Rank 4)

375 - 449 (Master):
Toughness (Rank 5)

450+ (Grand Master)
Toughness (Rank 6)

Happy Mining!



Link: http://www.wowhead.com/?spells=11.186