Bloodstone (movie, 1988)

When a newlywed American couple goes to India on their honeymoon, little do they realize that they are about to go on the adventure of a lifetime. A huge ruby from the time of the Indian Maharajas has been stolen and placed in the backpack of the Americans. When the bad guys realize this, they kidnap the wife... Now the husband and his Indian friend (played by a famous Tamil Indian actor) must go out to save her.