In general:
On production of some items (mainly things from tilled fields, and mines you find with dowsing rods) it goes like this:
you have a composition of the start item (seeds or dowsing rods) : (w,x,y,z) in the four elements (salt, mercury, sulphur, lead)
On "producing" something (finding a new place to build a mine, or harvesting the crops on a tilled field), the four values are randomly changed by small amounts (the sum being 1.00 in pretty much all cases but rounding errors). The larger the sum of the squares of the four values is, the more pure an item is. You can "grind purity" by only using the new items which have a higher purity than the start item. Do it until you hit maximum purity. Say our new item now has (w-0.1,x,y,z+0.1). Note there is no guarantee the purity will increase! The resulting item might well (and often will, in later stages) have a lower purity than the item you started with.
For example, a (0.25,0.25,0.25,0.25) is the least pure you can get with a multiplier of 1. When you would have only (0,0,0.50,0.50) the item is a lot more pure, with a multiplier of four. Finally, the maximum purity you can have is 100% in a single element, for example (1,0,0,0). This has multiplier x10 (you can check the formulas
here). The multiplier is not restricted to integer values, btw.
This turned out a bit longer than I originally planned
In conclusion, you shouldn't be bothered until you start farming/mining
Posted: Fri Feb 01, 2013 7:22 pm
but purity because increases the "stats" of an item, for something like lover's lockets which is an inspirational it increases the amount of proficiency gained, for food it increases amount healed, etc. How you raise it is variable, and what you want to raise factors in (salt, sulphur, etc.) But as I said, for more in depth than this just use the search function.