The Hatton necklace collection combines brushed stainless steel with natural stones, elegantly designed to coordinate with the Hudson Ring collection.- STONE: Black Onyx (strength, perseverance, and the ability to overcome challenges)- SIZE: Adjustable- MATERIAL TYPE: 316L stainless steel, 18K gold PVD plated- FINISH: Brushed- DURABILITY: Waterproof, heatproof & sweatproof