Diablo Wiki
"Blood Stones can range 50 feet or farther from magma, however, if they do so, they slowly turn to stone, suffering continuous damage. Once turned completely to stone, they are impervious to normal attacks. Should a source of molten stone erupt within 50 feet of their location, they molt into a full strength Blood Stone."

- Monster summary(src)

Blood Stones are a breed of Magma Demon in Diablo.

Blood stones are also a vital part of the Arkaine's Valor quest. You have to find 3 Blood stones, each of them guarded by 2-3 Horned Demon creatures and insert them into the Pedestal of Blood to pave the way to Arkaine's Valor.

Stats[]

Blood Stone
Property Normal Nightmare Hell
Type Demon Demon Demon
Level found in 8–10
Monster Level 14 29 44
Experience
Health points 55–75
Damage 2–12
Attack Rating
Defense
Fire Reaction Immune Immune Immune
Lightning Reaction
Magic Reaction Immune Immune Immune
Opens doors Yes
Follows around Yes

VariantsMagma DemonBlood StoneHell StoneLava Lord