As of August 23, 2015, no live official trademarks were found on USPTO.gov for the exact term
Being gem and rock people, we're not sure we want to sell this one; it's one of the best words in the field of gemology, given that refraction is an important consideration when determining a gem or mineral's value.
Also, this name could be used for an eyeglass and/or contact lenses business, either bricks and mortar or online store.
So we're thinking, thinking, thinking...
* * * * * *