What does MCO stand for stamped on a gold chain necklace that reads 120 14K MCO?

In the context of jewelry, "MCO" typically stands for "Manufacturing Company." The inscription "120 14K MCO" indicates that the gold chain necklace is made of 14-karat gold and has a weight of 120 units, likely referring to a measurement in milligrams or a specific length. This marking helps identify the piece's quality and origin.