Inkstones function as the currency in the Higher Planes, including the Infernal Realm. They can only be produced by a Sovereign.
Azurite is a variety on the inkstone, with an exchange rate of 1 azurite netting 1000 inkstones.
Inkstones and azurites, as they have been created by a Sovereign and thus contain a little bit of its power, can be refined into Sovereign's Might, although with tremendous effort and at a huge cost.
It has been shown that the different currencies can all be used within the Higher Planes, as Linley used inkstones inside the Netherworld instead of Netherstones, at a 1:1 rate[1].
Variety[]
Netherstones - The netherstones of the Netherworld were comparable to the inkstones of the Infernal Realm.
Pricing[]
In the Infernal Realm, Demigod Artifacts cost approximately 10 inkstones, God Artifacts 1000 inkstones and Highgod Artifacts around 1 million inkstones.
A Demigod Spark is around a hundred inkstones. God sparks are worth ten thousand inkstones, while Highgod sparks are worth ten million inkstones[2].
According to the rules, returning to a material plane will cost each Highgod one trillion inkstones, and each Highgod can bring ten Gods with them[3].
A Seven Star Fiend of the Infernal Realm generally would possess one trillion inkstones in worth at most.
Generally one drop of Sovereign's Might costs 100 trillion inkstones.