There are eight WEAPONs in the world of Final Fantasy VII.

Jade WEAPON om Before Crisis
Ruby, Emerald, Sapphire, Diamaond & Ultimate WEAPON in Final Fantasy VII-1
and
Omega (DoC) and Chaos (FF VII/FF VII DoC) (both of them are stated to be WEAPONs because of what they do in the Ultimania, even Chaos and about Omega - even in Dirge of Cerberus it is mentioned to be something like the WEAPONs)

Of course Chaos is something special, because it doesn't even look like the WEAPONs we know other than Omega which does look like one.

I only want to mention it. Of course you just want to know the WEAPONs of Final Fantasy VII-1.