This asset won't work out of the box, because it needs two materials and different shading. It's high poly, because the subdivision modifier had to be applied to the metal part. The diamond mustn't be subdivided. The material settings and the diffuse texture are quite useless. They only exist, because MH needs them. Material setup works the same way as for http://www.makehumancommunity.org/clothes/diamond_ring_01.html. Tutorial can be found here: http://www.makehumancommunity.org/forum/viewtopic.php?f=4&t=13910