[Boron]

I see it this way :

For forging a clam you either need 10 water or 20 astral gems converted to 10 water .

So when starting to clamhoard 1 water gem is as valuable as 2 astral gems .

So earlygame 1 water gem has twice the value of a pearl .

Lategame the pearls are more valuable because you can convert them to every kind of gem . But since your main income will be astral pearls from clams it is not as scarce as the other gems .
And if you have 20 natural water income this is better then having 20 natural astral income because you can forge twice as many clams from the water income then from the astral income .

So water is earlygame damn important because it helps you a lot starting to hoard earlier + benefit earlier from it .