It doesn't really blow my mind, but the diamond is surprisingly large (I wouldn't want a smaller one), and is striking just because of its' opaque blackness and size.  It doesn't have a green hue that I can see (I noted somewhere that manufactured black diamonds have a green hue whereas Brazilian natural black diamonds do not)-- though for all I know it could be a black saffire; I'm not sure how I'd tell the difference though it is cut like a diamond.  I did replace the chain-- it's not that it looks cheap as much as it is just very thin for a big stone like this.  I replaced it with a cheap, but larger, chain and it looked really good.  Not mind blowing... but to purchase diamond jewelry at this price is something.