Exponential Elemental Weapons Damage?

I've just run across a Diablo II: Lord of Destruction tip that I have not tried out as of yet, but am eager to test this out and report back. If true, you could gain mega-elemental-damage on socketed weapons. Find a socketed weapon with an elemental damage bonus from a magical property and add gems which give the same elemental damage bonus. The elemental damage bonus goes up exponentially.

For instance: You find a three socketed war axe with a +2-5 fire damage already as a magic property. Then fill the empty slots with rubies, which give a fire damage bonus to weapons. See what the total fire damage inflicted is versus the sum total of the fire bonuses. Report your results in the comments section.