What mean OTC 10 K on the jewelry?

OTC 10K on jewelry typically indicates that the piece is made of 10-karat gold that has been produced using an over-the-counter (OTC) process. The "10K" signifies that the gold content is 41.7% pure gold, with the remaining 58.3% consisting of other metals. This marking assures buyers of the gold's quality and authenticity, suggesting a balance between durability and value.