Quoted By:
Commercial large diamond synthesis seems to focus on two markets -- optical components and jewelry. Diamonds for optics tend to be constructed using controlled vapor deposition (CVD), layer by layer, where the time and cost depend on the thickness, which usually needs to be no more than a few millimeters.
The other approach is to grow them in a high-pressure high-temperature environment, producing more 3-dimensional diamonds. Here you are competing with the jewelry market, so prices are figured as a discount over DeBeers monopolistic prices.
Natural diamonds of that size tend to be reserved for royal regalia.
