Gem Waster changes the amount of gems used when crafting a pickaxe. The game essentially crafts an amount of pickaxes equal to the amount of gems used and returns whichever pickaxe had the highest quality. This effectively make using Gem Waster the same as clicking on the craft a pickaxe button several times, i.e. crafting one pickaxe with 39 gems returns the same result as crafting 39 pickaxes using 1 gem each.
It is not possible to get a pick with a P value lower than 80% of the current blacksmith base power under any circumstances. With no upgrades in Blacksmith Skill, if you only look at "Pickaxe" type picks with no pluses, the range is between 80% and 130% -- the average is approximately 105%, right in the middle. If the type of pick is other than Pickaxe, or if there are pluses, the range is higher. So 100% should not be considered "average" at all.
Each upgrade of Gem Waster costs 9*10^(7n) where n = the upgrade number (1,2,3...). After you purchase an upgrade, you have the option use the gem waster at that level, or any lower level. When you set the gem waster to to use gems at level n you use the integer poirtion of (3.4)^n gems, rounded down. (So when n=2, you multiply 3.4 x 3.4 to get 11.56, then round down to 11.) That is, you can only use the number of gems listed in this table.
|#||Gems used||Cost||Modified Base %|
|0||1 - Start||0||100%|