Guild Wars 2

So it seems to me that not all sigils and runes are crafted, is that right? Some of them are just random chance drops from mobs in the world (already attached to items).

I’m looking for Superior Rune of Strength (x5), Superior Sigil of Strength and Superior Sigil of Purity. I know that the Sigil of Strength can be crafted, but what about the other two?

I have the same question, I would like to upgrade my exotic GS with a superior sigil of fire.

Im pretty sure the Sigil of Strength is 1 Orichalcum Ingot 2 Onyx Lodestone 1 Glob of Ectoplasm (Weaponsmith). But not sure about Purity or Fire.

Yes, as I mentioned I know that Sigil of Strength is crafted. What about Rune of Strength?