Black onyx pendant

This is a brand new black oxynx pendant. The person that I bought it from said it is sterling silver, but it it not marked. Smoke free home. Black Onyx A powerful protection stone, Black Onyx absorbs and transforms negative energy, and helps to prevent the drain of personal energy. Black Onyx aids the development of emotional and physical strength and stamina, especially when support is needed during times of stress, confusion or grief