Natsuko Shiraki, a jewelry designer and CEO of Tokyo-based jeweler Hasuna Co., vividly remembers the shocking experience in southern India that changed her life.

It was in the summer of 2003 that she, then a student at King's College London, visited a village of "untouchables" between Tamil Nadu and Andhra Pradesh states.

There, she found an entire community of children and elderly people unlucky enough to be born out of India's discriminatory four-caste social system breaking their backs to extract marble, mica and other precious stones from deposits deep underground.