Ashtadhatu


Ashtadhatu, also called octo-alloy is an alloy often used for casting metallic idols in Jain and Hindu temples in India.
The composition is laid down in the Shilpa shastras, a collection of ancient texts that describe arts, crafts, and their design rules, principles and standards. Ashtadhatu is used because it is considered extremely pure, sattvic of Sattva, in Hinduism, and does not decay, as also being restricted to those of Gods Kubera, Vishnu, Krishna, Rama, Kartikeya, and goddesses, Durga and Lakshmi.
Its traditional composition is gold, silver, copper, lead, zinc, tin, iron and antimony or mercury. However sometimes an alloy idol is termed ashtadhatu, even when its exact composition is not known. The metals were mixed in equal proportions and the finished idol was very rough to be thoroughly polished later on. Due to their sacredness and rarity, these pure idols are very susceptible to thefts.