[A_D_E_P_T]

This is really quite new. China and India, just over the past few years, have turned synthetic diamond production into a serious industry, and the fact that there are so many small producers is leading to a "race to the bottom" on pricing. A race we're now right in the middle of. Within just a few years, synthetic diamond might be nearly as cheap as synthetic ruby. (The raw materials are equally cheap, but making diamond is a more laborious and energy-intensive process, so it'll always be somewhat more expensive.)