You are admiring what I call a stunning specimen, a rarely seen Calliostoma formosense (Smith, 1907) measuring a very nice 51.9mm and graded F+++...an absolutely incredible form and a fantastic color pattern is displayed on this deep H2O specimen.  This beauty was trawled at 80-120m off Hengchun, S. Taiwan.  A former member of the Trochidae...today, it is included in the Calliostomatidae family which I totally agree, it's a species that deserves it's own family name!!  Both families are very high on my list of favorites.  Thanks for visiting our store today...and an excellent choice, too.