Hello, I'd like to know if the store "diamonds usa" 
http://www.diamonds-usa.com is legitimate and reputable.

Their prices are a lot cheaper than any other place I've seen, so I'm
wondering what the catch is.  FYI, looking for an engagement ring.

I am not going so far to say they are a scam (they are indeed
registered with the New York Department of State), but I am always
cautious when companies register their Web domain through an
anonymizing service.

Also a bit suspicious: The proudly present their Israel Diamond
Exchange Membership certificate (
http://www.diamonds-usa.com/diamond_rings/certificate-bursa.asp ) and
their Israeli Division Bank Letter (
http://www.diamonds-usa.com/diamond_rings/certificate-bank.asp ).
However, those are not actual scans. The important parts of the texts
are part of the website, not of the documents. Actually, these are the
only scanned parts of these "documents":
http://www.diamonds-usa.com/images/dusa-bursaletter.gif
http://www.diamonds-usa.com/images/let3bottom.jpg
http://www.diamonds-usa.com/images/dusa-bankletter.gif
http://www.diamonds-usa.com/gifs/bank2.gif

A bit strange, I'd say...

Scriptor

I might suggest contacting the Israel Diamond Exchange at their contact email
address (from their website) of: yuval@diamonds.com