Bone is a Runeword "SolUmUm" in Diablo 2 Resurrected (D2R). It requires these 3 runes to be inserted into a socketed item in the exact order: Sol + Um + Um . The eligible bases for Bone are the following: Body Armors . An important benefit coming from Bone:
  • The character will be more resistant to any elemental damage.
This is the only Runeword in the game that has X% Chance to cast Level X Bone Armor when struck attribute.
BoneBoneGreat Hauberk
Sol · Um · Um
Defense: 395 - 501
Durability: 50 of 50
Required Strength: 118
Required Level: 56
15% Chance to cast Level 10 Bone Armor when struck
15% Chance to cast Level 10 Bone Spear on striking
+2 to Necromancer Skill Levels
+(100 - 150) to Mana
All Resistances +30
Damage Reduced by 7
Socketed (3)
Trade items on d2trader.net

How to obtain Bone

The fastest way to get this item on Battle.net is via trading, you can use the Item Price Checker to see how much Bone is worth.
Another way of getting this Runeword is by farming the runes and the base. Find the drop rates of these items in the Item Database.

Bone bases

The best base for Bone is Great Hauberk. Below is a list of all eligible 3 socket bases for Bone.