Torrid 20" Chain Necklace with Gem Accents

Purchased probably 2 or 3 years ago. This necklace measures about 20.5 inches end-to-end including a 3 inch extender and is made up of dark gray metal chain links. Every sixth link has white gem accents. Because of the design of the necklace, it can be written loosely, or tightly like a choker. It has a lobster-claw clasp. There is no flaking color or tarnishing. I wore it maybe twice.