Render issue

When I render viewport and pick metal as my material why does it look like this …see video

  • you have very low polish value, set it closer to the maximum, like 97% or 98%.
  • metals (and glasses) look good only in context with something to reflect. You need to have something in the environment, in the very least custom reflection environment slot with a good hdri

The same concepts as per Nathan and similar /related ones are applicable with gems / gemstones to.