What's the SD on the diamond cutting industry?

I was once told (no cite) that all jewelry-grade diamonds go through either New York or Tel Aviv for cutting. Is this true? If so, why?

I know that the diamond mining industry is essentially held by a monopoly, but is it the same situation for the cutters? Is it a closely held trade, passed down from generation to generation, or is there just not enough demand for the service for any other shops to spring up?

It’s not true. From the Wikipedia article:

“One hallmark of the trade in gem-quality diamonds is its remarkable concentration: wholesale trade and diamond cutting is limited to a few locations. 92% of diamond pieces cut in 2003 were in Surat, Gujarat, India.[1] Other important centers of diamond cutting and trading are Antwerp, London, New York, Tel Aviv, Amsterdam.”