Mason & Madison Co. Has Been Featured On. Item Details:. • Lab-grown Diamonds, Premium-grade PVD 18K Gold-plating for a durable and scratch-resistant accessory that withstands all the elements of an active lifestyle without sacrificing a luxurious look.. • Chain length: 17.5 in, Extension length: 2.2 in. • Diamond Brilliant Benefits: the Energy of POISE + PURITY + VISION. • Golden Benefits: the Energy of CONFIDENCE + SELF-WORTH + COURAGE. • Dispatched from New York, USA