Preheat a gas or charcoal grill to medium-hot (375 to 425 degrees F).
Prepare the grill for indirect cooking: For a gas grill, turn off the center burner; for a charcoal grill, bank the coals on either side; place a drip pan under the grate between the heat sources.
Score a diamond pattern into the ham, about 1/8-inch deep into any fat.
In a small bowl, combine the coriander, paprika, cumin, cinnamon, and cloves. Rub the spice mixture over all sides of the ham.
Place the ham, flat side down, in the center of the grill over the drip pan. Cover and cook, adding briquettes to a charcoal grill as necessary to maintain the heat, until the internal temperature of the ham reaches 140 degrees F, 1 1/2 to 2 hours or 15 to 18 minutes per pound.
Meanwhile, in a small bowl, combine the marmalade, orange juice, and sugar.
Brush the marmalade mixture over the ham.
Cover and grill 5 minutes, until the glaze is lightly caramelized.
Remove the ham from the grill, transfer to a cutting board, and let rest 15 to 30 minutes.