A diamond is spotlessly pure and indestructible. The Sanskrit word means "unbreakable or impregnable, being durable and eternal". As such, the word vajra sometimes signifies the lighting-bolt power of enlightenment and the absolute, indestructible reality of shunyata, "emptiness."
Buddism integrates the word vajra into many of its legends and practices. Vajrasana is the location where the Buddha attained enlightenment. The vajra asana body posture is the lotus position. The highest concentrated mental state is vajra samadhi.