How many Weapons are there?

[Mo-Nercy]

There are five Weapons in FFVII. You've correctly named 3 of them. The other two are Ultima (who you kill to get Cloud's best weapon) and Sapphire (who you don't fight in-game but gets shot in the face by the Junon Cannon).

I mentioned Ultima in the first sentence; it's the one that almost runs into the Highwind as it takes off.

And I always thought Emerald was the one that got shot by the Sister Ray; that's why you fight it in the ocean area around Junon.

My apologies, you've correctly named 4

But no, Emerald and Sapphire are different Weapons. You can tell by the colour, and also just their build. Sapphire was more sleek and Emerald, quite bulky.