Electrum Chest is the 81-slot top tier of the Ala Industrial chest line: nine rows of nine slots, 27 more than the 54-slot Gold Chest it upgrades. The chest needs no energy to store or open — it is a passive container that works the moment it is placed. The interface shows six of the nine rows at a time, and a scrollbar (mouse wheel, slider drag, or track click) reaches the rest; shift-click deposits items into rows that are currently off-screen. Visually the Electrum Chest reads as pale gold, lighter and cooler than the golden tier, because electrum is the mod's gold-and-silver alloy — with the same animated lid and the same metallic open sound as the iron chests.
Crafting takes a ring of eight Electrum Ingots around one Gold Chest on a crafting table, and the upgrade keeps the full contents of the old chest. Two Electrum Chests placed side by side facing the same direction merge into a 162-slot double chest that hoppers and item pipes treat as a single container, while different tiers never merge. A comparator reads the fill level, the chest can be waterlogged, and breaking it drops the chest itself and spills the contents on the ground. Each Electrum Ingot comes from one gold ingot plus one silver ingot in an Alloy Smelter for 1200 EU and about 7.5 seconds, so the jump from 54 to 81 slots is the most expensive upgrade in the chest line — worth it when a whole storage room must fit into one block.