This necklace is on a polished hemp cord, with adjustable double slip knots so you can wear it at many lengths. The beach glass is really cool. It is half of a bottle bottom, where the bumpy texture is almost completely worn off, but there's still a little of it left, and a couple characters on the one side. It is a nice sized piece and available on Etsy at:
https://www.etsy.com/shop/BeachWalkArtByKim