I have what I think is a ruby of excellent quality. The diameter is around 11mm. It appears to be around a 10ct. How do I authenticate it if I want to sell it?
That's quite large and, if clean, would raise suspicions about whether it is natural or man made. If you think that it could be natural I would suggest sending it to the GIA for a "Colored Stone Report". Please see their website for information as to how to proceed here: http://www.gia.edu/lab-reports-serv...orts/index.html