Gold plated ring. Measures approx 0.25"" H. JOOL-WL15. OPEN BAR KNUCKLE RING. Born and raised in Miami, Florida, Martha Calvo began designing jewelry that was unique and rare, capturing her personal sense of style. Inspired by her love for fashion and fueled by her desire to deliver a product of the highest quality, designer Martha Calvo created a unique line of jewelry in 2006. Today, Martha Calvo is part of the must haves that fuse uptown elegance with a downtown edge. Adding the perfect balance of chic sophistication with a sprinkle of glam to any accessory that can be worn for any occasion, day or night.