Amethyst pendant of the tides -- what gem would you put in?

[Frohnatur]

On my warrior twink I got a lvl 25 amethyst pendant. Its warrior class bound and character bound. These are the stats:

str 30, int 14, 4.0 dmg (!)

the damage value makes it extreme interesting, even for higher levels.
but what gem would you put in to make it competitive at, say, lvl36?

or better asked what differences regarding the stats would the fire or glac gem do?

[Sacrifice]

Maybe strength, most warriors use it thus strength or maybe dex to balance it.