Yes Mankalong four-leaf clover necklace is genuine if it is equipped with Mankalong word seal (one positive and one negative double M), factory word seal and gram heavy word seal. Mankalong Jewelry Co., Ltd. is a large international professional jewelry group involved in jewelry design, manufacturing, wholesale, retail and other fields. It is one of the most important strategic partners of De Beers Group, World Gold Council and International Platinum Association in China.