1 Answer. The only thing you can do with Hallownest Seal, Wanderer's Journal, King's Idol, and Arcane Egg is sell them to Relic Seeker Lemm for Geo. If you don't need the Geo right away, consider waiting to sell them because unlike your Geo, these items are retained on death.

How much is an arcane egg worth?

Hollow Knight

A visual guide to the four rare Arcane Egg collectibles which sell to Relic Seeker Lemm for a whopping 1200 geo each.

Are Hallownest seals important?

These ornate seals were the official symbols of the King and his Knights, and were treasured by those who carried them. The King and his Knights are long gone, but the seals still hold value as curiosities.