Can I replace a drop-in sink with a counter-top mounted sink?
Al long as it covers the old cutout and the original top is strong enough to carry the weight, there will be no problem. Vessel sinks are usually held in place by the drain to a degree and sealed at the base with a good grade of caulk. Yours is heavy enough, if it is the same bulk as the one pictured, its weight alone will keep it in place, but please seal it down with a good water based, mildew proof caulk.