Bone is a Diablo 2 Resurrected runeword created by combining sol + um + um into a 3 socket body armor. It requires at least level 47 to equip.
The +2 to Necromancer skills, high mana bonus, and decent resistance makes it a viable option for any Necromancer build. It should be noted that when the Bone Armor procs, it overrides the existing (possibly higher level) Bone Armor. Bone is a medium priced Necromancer runeword, although the two Um runes can be considered expensive.
Bone has a 15% chance to cast a level 10 Bone Armor when struck. When active, Bone Armor absorbs a flat amount of physical damage. It can be seen as the physical equivalent of Cyclone Armor
|Bone Armor level|
|damage absorbed by shield||70||80||90||100||110||120||130||140||150|