I'd never heard of quartz counters. Anyone had good or bad experience?
it's probably a large crack on the inside and it looks like a shard of metal. I have seen this before.
Could you post a few photos from different angles? Some metals will often concentrate in the same hydrothermal fluids that deposit the quartz. Gold and quartz are commonly associated for example. It could by molybdenite, it's a silvery metal sometimes associated with quartz-rich rocks
Quartz can have a number of crystalline inclusions, but one of the more common ones is rutile (Titanium Dioxide).
