The DL site says, "Delta is not responsible or liable for cash, camera equipment, commercial effects, computer software and equipment, electronic equipment, fragile articles, jewelry, lifesaving medication, negotiable papers, irreplaceable business documents, works of art or other similar valuable items contained in checked or unchecked baggage. These items should be carried by the passenger."
I would not take a chance. In addition you are limited to the International Liability Limit (governed by the Warsaw Convention) for your other checked items: $9.07 per lb. up to $640 per bag (U.S. Dollars) unless you purchase extra insurance at checkin.