Inside Foragers Crystal Cave is a room which contains 3 Small Chests. The only issue is that they are all frozen and can’t be opened. Tools like the Fiery Pickaxe which can usually melt ice won’t give access to the chest.
Instead, you have to complete a small puzzle. The same puzzle that you will have to complete in order to obtain the boss key. So, to start, progress through the Crystal Cave as much as possible until you find a Big Blue Chest. You will need to take some minecarts in order to reach this area.
Inside this chest is the Ice Rod, which you need to continue in the cave. Head back to the area where the Boss Key and 3 Small Chests are. Use your Ice Rod on the Braziers, which are the flaming pillars. The base of them will freeze, allowing the laser to pass through it in all directions.
Guide the laser from the Braziers so that they hit all 3 chests, melting the ice around them. You can now search the chests. Hopefully this guide was of use to you, if it was, you might be interested to read some more Forager Guides that we’ve put together!