Diablo 4 will feature numerous currencies which are used in different ways in Sanctuary.
Gold is the basic currency as it was in the previous games in the series.
Murmuring Obols can be used at the Purveyor of Curiosities and are used for gambling purposes. Murmuring Obols are acquired by completing events throughout Sanctuary.
Seeds of Hatred are converted into Red Dust at the Altar of Extraction. It is specifically tied to the end-game and PvP. Red Dust can be redeemed at PvP Cosmetic and Mount Vendors for ornamental rewards.