Coppermind:Welcome/Featured Article/Feruchemy
Featured Article: Feruchemy[edit]
“Feruchemy, it should be noted, is the power of balance. Of the three powers, only it was known to men before the conflict between Preservation and Ruin came to a head. In Feruchemy, power is stored up, then later drawn upon. There is no loss of energy—just a changing of the time and rate of its use. ”
—Sazed describing Feruchemy in the Words of Founding
Feruchemy is one of the three prime manifestations of Investiture on Scadrial. The natives of that world consider it one of the three Metallic Arts.
Feruchemy is an end-neutral manifestation of Investiture that allows the user to convert certain attributes into Investiture and store them in metal that they are in physical contact with, and to later retrieve them from the metal. Although it is generally inherited or obtained through Hemalurgy, there are other ways to become a Feruchemist, involving the Scadrian God Metals, atium and lerasium. As an end-neutral art, Investiture is not gained from an outside source (as it is in end-positive arts) and Investiture is not permanently lost (as it is in end-negative arts). Ordinarily, when a Feruchemist is tapping an attribute at the same rate it was stored, they are able to get out exactly what they put in, for example, if they store 50% of their strength for one hour they can tap that and be at 150% of their strength for one hour. However, if the Feruchemist taps at a greater rate, then some of the attribute is lost, to facilitate the compression of the Investiture. This means that a Feruchemist who stores 50% of their strength for one hour might only be able to stay at 200% for 25 minutes, rather than a full half hour. The more a Feruchemist compresses the attribute, the more is lost. While a Feruchemist can only store attributes at a reasonable rate, there isn't an upper limit of how much they are able to tap at any given time.
The type of metal determines what attribute can be stored within it. Pieces of metal that have been charged by Feruchemists are referred to as metalminds in general, or more specifically as the type of metal with an added "-mind" suffix. The act of charging, or Investing, a metalmind is referred to as storing and the act of retrieving the stored attribute is referred to as tapping. Feruchemists are capable of innately knowing how much of an attribute is stored within a metalmind at any time, as long as they are physically touching the metal mind, in the same way an individual can know how tired they are.
A larger piece of metal will be able to store more of an attribute, but the scaling is not linear; there are certain thresholds of size where the amount of attribute that can be stored increases. If a metalmind is broken, the stored attribute will be split among the pieces. This is because the power inside the metal acts like a gas acts inside a jar. It is possible to store and tap using molten metal (setting aside the conventional hazards of touching molten metal) which would have some effect on the stored Investiture. If the molten metal is mixed to form an alloy, however, the Investiture will become inaccessible, even if the alloy in question is Feruchemically viable. If the alloy is Feruchemically viable, a Feruchemist will not be able to store as much of an attribute as they could in an identically-sized metalmind: while the original Investiture is inaccessible, it does still take up "space" in the metalmind.
Ordinarily, a Feruchemist's stores are keyed to their Identity and are inaccessible to another Feruchemist. However, other Feruchemists can sense the presence of the original Feruchemist's stores, but only if they have the ability to use that attribute themselves.
In order to get the most storage out of a metalmind of an alloy, the metal has to be alloyed in a specific combination of metals. If the metal does not have the right mixture, it is considered impure. This is likened to how Allomancers require these 'pure' metals as well. If a metalmind is not pure, it will not hold as much charge as one that is alloyed correctly with the same size.