Here, we describe the aqueous phase synthesis of Ni-B and Co-B MG shells on metal nanocrystals and demonstrate that the synthesis approach is rapid and independent of core shape and size. Au and Pt cores are coated with Ni-B and Co-B shells and their mechanical stability, optical behavior, and magnetic properties are investigated. The particles are also extremely stable and can withstand more than 55 GPa of hydrostatic pressure via a diamond anvil cell (DAC) without crystallization. NiB-coated Au nanoparticles retained the plasmonic properties of the Au core. NiB and CoB coated Au nanoparticles display super-paramagnetic and ferromagnetic behavior, respectively.