Necklace with a turquoise in color medallion on a black cord that is adjustable for an extra 2.5" with a lobster claw clasp. Unknown material. Approximate measurements: Medallion 1.75" x 1.75", cord 18.5" to 21". New to Poshmark? Sign up using my referral code to receive $10 off your 1st purchase. Enjoy! ~ Cindy Referral code: CLTREASURECHEST