Definition:
Bone magic is the practice of working with physical remains (bones, ashes, grave dirt) to access ancestral power or create powerful talismans. 

Why Bones:
• Bones are the last physical remains.
• They hold the essence of who someone was.
• Bones are durable, lasting connections.
• They serve as anchors for spirit.
• Bone contains life force memory.

Types of Bone Work:
• Ancestor bones for altar work.
• Grave dirt for various spells.
• Bone divination sets.
• Protection talismans with bone.
• Ngangas in Palo (contain bones)
• Necromantic tools made from bone 

Ethics:
• NEVER steal from graves.
• Use ethically sourced bones (antique, found, inherited)
• Treat all remains with utmost respect.
• Get permission from the spirit.
• Proper disposal when finished  

Source:
Necromantic and folk magic traditions, The Syncretist Realm, TheSyncretistRealm.com.