I'll take a try:
Q2: SiC is used for abrasives, but this material is manufactured cheaply using conventional ceramic techniques. Companies like Cree and C3 deal in single crystal SiC which is much more expensive to manufacture because the perfection of the crystal depends on near zero impurity contamination and perfect temperature control during the crystal growth. C3 isn't interested in this market because it is very low margin.
Q4: I'm guessing, but if the SiC substrates which Cree sells today were sold in terms of carats, rather than diameter, they would carry a pretty heft carat price, say $200/carat (???). One would merely have to do the math: surface area x thickness x density SiC x g/carat granted that a 1.375" SiC wafer retails in the ball park of $5-800. There is a good chance that moissanite will sell at the same price given that the fabrication methods are quite similar. Gems would require cutting and polishing, wafers sawing and polishing. I don't know what the market would bear for a fake diamond. Does anyone know the going wholesale rate for real diamonds per carat. I'd guess Moissanite wouldn't command more than 25% of that price.
My own question: Moissanite is a form of SiC, which material scientists usually label by more mundane names, such as 6H-SiC, 2H-SiC, 3C-SiC etc... My question is what polytype of SiC is Moissanite? I'd guess 3C-SiC since if it to be a diamond fake, it had better have the similar cubic crystal structure so that its faceting is the same. Anyone know for sure?
I'm also interested to anybody's insight into Q3. SiC substrates are moderately transparent, but not clear like diamonds. To make Moissanite, I'm curious if you can just use the same boules used for SiC substrates, or if the cleanliness requirements are higher, or if specific impurities must be incorporated in controlled amounts.
Looking forward to some answers. |
