And make Stealth Rock 50% stronger on each each time the foe switches?
How I wish it were possible......
No, the elemental gems do not effect status moves at all. Nor do they effect set damage moves. Source And I am very grateful that it does not make stealth-rock even more annoying than it already is, it would immediately kill all Pokemon with 4x Rock weakness and make Fire/Ice/Bug/Flying types unusable lose half their HP.