Geo

Description
''The currency of Hallownest, made from fossilised shells of various forms. Can be traded for goods or used as toll in various old mechanisms.''

Function
Currency, used to buy goods from merchants or to pay tolls. 3000 Geo is also required to obtain the reward from the fountain in Ancient Basin.

How to Acquire
Geo can be gained in several different ways:
 * Defeating enemies
 * Destroying Geo deposits
 * Opening chests
 * Selling relics to Relic Seeker Lemm
 * Turning in Grubs to the Grubfather
 * Completing a Trial at the Colosseum of Fools

Acquiring More Geo
The Gathering Swarm charm allows flies to come and bring dropped Geo to the player. Fragile Greed increases the amount of Geo enemies drop. Together, these items can make farming for Geo far more efficient.

Enemies in endgame areas tend to be the best sources of Geo. Hoppers at the Kingdom's Edge are plentiful and drop significant amounts of Geo, so do Great Hoppers. Many enemies in the Forgotten Crossroads also drop a lot of Geo once the Crossroads become Infected. In the early game, Husk Guards can be useful sources of Geo. Many City of Tears enemies are good sources as well. Great Husk Sentries drop a lot of Geo, though they can be hard to defeat and thus inefficient to farm.

Selling relics to Lemm is particularly useful because, unlike your Geo, these items are not lost upon death.

In Steel Soul mode, Rancid Eggs can be sold to Steel Soul Jinn for Geo (since their other function becomes useless as death is permanent).

There are some good one-time sources of Geo as well:
 * In the City of Tears, a hidden enemy known as the Gorgeous Husk can be found in a hidden room not far from King's Station. It drops 420 Geo upon death, even more with Fragile Greed.
 * In Kingdom's Edge, there is a hidden passage accessible by breaking a wall in a room with a Great Hopper and a lot of spike pits. Descending very deep into this passage takes the player to the biggest Geo deposit in he game, from which several hundreds of Geo can be acquired.