In Path of Exile, Voidstones are crucial endgame items that allow players to upgrade their Atlas maps to Tier 16, enabling efficient farming of the highest-tier content PoE 1 Currency. There are four unique Voidstones, each dropped by a specific Pinnacle boss:
1. Decayed Voidstone from Uber Elder
2. Ceremonial Voidstone from The Maven
3. Grasping Voidstone from The Eater of Worlds
4. Omniscient Voidstone from The Searing Exarch

How to Get All Voidstones
1. Defeat Each Pinnacle Boss  
To obtain each Voidstone, you must defeat the corresponding boss. These fights are challenging and require well-prepared characters and strategies. The bosses are found by progressing through the Atlas and completing their associated endgame content. For example, Uber Elder and The Maven are fought after gathering fragments and activating special maps or invitations.

2. Use the Maven’s Influence and Invitations 
To farm fragments and prepare for these fights, run Shaper and Elder influenced maps with the Maven’s influence active. After completing four such maps, visit Kirac to activate Maven’s Invitations (Shaper or Elder) and defeat the formed or twisted versions of these bosses in the Maven’s Crucible. This method increases fragment drops, which are necessary to summon the bosses.

3. Repeat and Progress 
Players typically cycle through farming these bosses to collect fragments and eventually summon Uber Elder. Once all four bosses are defeated and their Voidstones collected, you can socket them into your Atlas.

4. Socketing Voidstones  
Voidstones are socketed into four special slots on the Atlas. Once all are placed, every map on the Atlas is upgraded to Tier 16, allowing players to farm any map at the highest tier. Additionally, each Voidstone grants a 25% chance for maps to drop one tier higher and a small chance to upgrade Tier 16 maps to Tier 17.

Tips for Efficient Farming
1. Use the Remnant of the Past passive on the Atlas skill tree to improve fragment farming.
2. Rotate Maven’s Invitations (including the Feared invitation for more advanced farming) to maximize fragment drops.
3. Farm Conqueror maps to gather fragments for Uber Elder.
4. Improve your build and gear to handle these difficult bosses, as they require strong survivability and damage output.
5. If struggling, consider buying carries for Voidstones early in the league to speed up progression.

Summary
Collecting all four Voidstones is a key milestone in Path of Exile that unlocks full Tier 16 Atlas farming. This requires defeating the four Pinnacle bosses—Uber Elder, Maven, Eater of Worlds, and Searing Exarch—by farming fragments through Maven-influenced maps and invitations. Once obtained and socketed, Voidstones enhance map tiers and drop rates, enabling efficient endgame progression and farming PoE Currency buy.