The famous 4C  that is the of Diamond pricing Bible doesn’t work for Sapphire. When I started my first steps in the trading, a trader told  me ” Sure we have the 4C when we price the sapphire C1 – color, C2 – color, C3 – color C4 – color” :-) for a Sapphire color

From GEM GUIDE   “Gem Market Pulse May 2015” “Of major concern in the ruby market is the continual attempts to pass off glass composite rubies as some form of simply another “treated” ruby. This is not a treatment process. This is a combination of non-ruby material, i.e., lead glass, and