Black one shoulder mini dress with sparkle detail

Mid length black dress, purchased from a local boutique and worn once for a wedding. Beautiful gemstone detail on the strap and at the top. Slip under layer. Bodycon, tight fitting dress, fits more as an xs than an s I would say. The strap has been taken in to fit more of an xs as well, but it can be taken back out easily. The dress is similar to something you would buy at le chateau, which is why I tagged it as the brand. Great condition, no known flaws. Unknown material.