Add the coriander and cumin to a small skillet and heat over medium heat. Swirl until the seeds are golden and slightly fragrant, about 3 minutes.
Let cool slightly, and finely grind in a spice grinder.
Combine the spices with the cilantro, rum, jalapeno, onions, red pepper, pineapple, lime juice and zest in a medium bowl. Season with salt and pepper. Refrigerate until chilled, at least 1 hour or overnight.