Fossil

Fossils are a special type of currency that can be socketed into resonators to modify the crafting behavior in specific ways, released in the Delve league.

Fossil belongs to Stackable Currency item class in terms of the item filter.

Obtaining
Some fossils are tied to specific Delve nodes.
 * Crystal Spire:
 * Haunted Tomb:
 * Humid Fissure:
 * Molten Cavity:
 * Stonewood Hollow:
 * Time-Lost Cavern:

Other fossil are either spawn along the road between nodes, behind fractured walls, or Smuggler's Stash encounter, etc.

There are additional ways to obtain fossils by random:
 * (random fossils)
 * Vaal Vessel with end-game vaal side area mod
 * unique synthesis map with map mods (map mod only be revealed after using the map item in map device)
 * Legion with fossil reward type (random fossils).
 * (random fossils)
 * Blight with fossil reward type (random fossils).
 * Metamorph with fossil reward type (using Metamorph sample with ; drops random fossils)
 * Delirium with fossil reward type (drops random fossils), from wild Delirium or map crafted with or  by random.
 * Wild Homunculus crafting reward (exchange fossil with another fossil by random)
 * Heist Delve reward chest (drops random fossils)
 * Ritual spawns random purchasable items, including fossils.
 * Trials of Chaos (or known as Ultimatum) spawns random rewards, including fossils.

Delve
Note that the node Smuggler's Stash does not tie to any biome

Delve modifiers
Some fossils can also add special Delve fossil-only modifiers, however, these modifiers are different from Delve drop-only modifiers from specific Delve nodes. Delve drop-only modifiers are drop-only while fossil-only modifiers are from fossil only. They both cannot be crafted from other sources. Lastly, the game developer, GGG, removed a large chunk of Delve fossil-only modifiers from the spawnable pool. Those legacy modifiers can only found from existing item which can be obtained from trading with other players in permanent leagues. GGG also added new influence modifiers that similar to the removed fossil-only modifiers, but not all removed Delve modifiers have similar influence modifiers.

Related divination cards
The following divination cards can be exchanged for fossils:

Version history

 * Item modifier tags have been entirely reworked with a goal in mind of consistency and simplicity. These changes have negligible impacts to the odds of various modifiers appearing on rare items naturally, but may have impacts to the results of certain crafting methods.
 * As a result of the above changes, several fossil descriptions have changed slightly.


 * Fossils can no longer craft any prefix or suffix mods that cannot be obtained elsewhere, with the exception of those granted by Faceted, Bloodstained and Hollow Fossils. Implicit modifiers (such as the one which changes an item's vendor sell price) remain. The following mods have been relocated, while all others can no longer be obtained:
 * On Boots: +2 to level of socketed Fire Gems (now from Warlord's Influence), +2 to level of socketed Cold Gems (now from Redeemer's Influence), +2 to level of socketed Lightning Gems (now from Crusader's Influence), +2 to level of socketed Chaos Gems (now from Hunter's Influence), +1 to global level of raised Spectres (now from Elder's Influence).
 * Helmet: Nearby Enemies have -x% Fire Resistance (now from Warlord's Influence), Nearby Enemies have -x% Cold Resistance (now from Redeemer's Influence), Nearby Enemies have -x% Lightning Resistance (now from Crusader's Influence), Nearby Enemies have -x% Chaos Resistance (now from Hunter's Influence), Nearby Enemies take x% increased Physical Damage (now from Elder's Influence), increased effect of Fortify (now from Crusader's Influence).
 * Body Armour: Socketed Attacks have -15 to Mana Cost (now from Warlord's Influence), x% increased Aura Effect on you (now from Redeemer's Influence).
 * Quiver: x% chance to gain a Frenzy Charge on hitting a Rare or Unique Enemy (now from Elder's Influence).
 * Belt: Increased Chaos Damage (now from Hunter's Influence), increased Physical Damage (now from Elder's Influence), increased Elemental Damage (now from Shaper's Influence), increased Energy Shield from Body Armour (now from Shaper's Influence, and now a Prefix), chance for double Armour Effect when hit (now from Elder's Influence, and now a Prefix).
 * Rings: Fire/Cold/Lightning/Physical/Chaos leech modifiers can now exclusively be found from special elemental Delve encounters.
 * Weapons: Socketed Attacks/Spells deal x% more Damage (now found from Shaper's Influence), chance for Poison/Bleeding inflicted with this weapon to deal more damage (now found from Elder's Influence), chance to Intimidate on Hit (now found from Hunter's Influence), Auras from your Skills grant increased Damage to you and Allies (now from Redeemer's Influence).
 * Jewels: Damage penetrates 1% Fire/Cold/Lightning/Elemental Resistance (now from Corrupted implicits).
 * Glove, Amulet and Shield Fossil-exclusive modifiers can no longer be obtained in any form. Existing items will be unchanged.


 * Introduced to the game.
 * }