Not all live rock at any given LFS
is cured. When I receive shipments, it may take sometimes up to two months to cure out completely. Generally speaking, if you can smell any nasty funk, it is not fully cured yet. When in doubt, you would do best to place the rock in question in a holding tank or Rubbermaid container for a week or so. When there is no detectable ammonia or nitrite, the rock is "cured" and can be safely placed in the display tank. While the rock is "curing", be sure to keep the calcium and carbonates at the highest acceptable level. This will reduce further die-off.