The perfect showcase for one-of-a-kind stone, Derbys case wraps elegantly around the Petoskey dial like two horseshoes. The Petoskey stone is treasure sought out by many who visit the beaches of northern Michigan. Varied on the surface, each stone is fossil of colonial coral believed to have lived in waters more than 350 million years agoand no two are alike. Slim gold hands and polished gold numerals complete the look. five-link bracelet, crafted from PVD gold stainless steel, makes this Derby true winner with an everyday elegance. Note: Petoskey stone can vary in pattern and color. No two are the same.