Combine the garlic powder, dried rosemary, sea salt, and black pepper to create a rub.
Layout all the lamb chops and drizzle with oil then rub it evenly over the meat. Sprinkle with the rosemary rub. Wrap the lamb chops in plastic wrap and chill for at least 1 hour and up to overnight.
Remove the lamb chops from chilling and place them next to the grill while heating the grill. This will help bring the meat to room temperature quicker.
When the grill is at a medium cooking temperature rub the grill grates with oil.
Add the lamb chops to the grill, close the lid on the grill, and cook for 4 minutes.
Turn the lamb chops then close the lid and cook for an additional 4 minutes. Check the doneness with a temperature gauge. The lamb chops should be removed when the temperature is 5 degrees below your target temperature, as there will be carry-over cooking after being removed.