Panchagni

Panchagni (fire with the five items burned together is called panch-agni) are organic material and when they burnt in presence of copper it creates copper oxide, copper sulphate, copper chloride and other gases.

Apart from its extensive heat transmission, copper is also considered as the best metal for this kriya due to its productive nature of creating high end chaitanya shakti (spiritual healing energy) which cannot be achieved from any other metal.

The pyramid shaped vessel enhances the spiritual and positive vibrations thus created from this process.

Pyramids are capable of drawing positive energy and vibration from atmosphere.

It is therefore even very beneficial to do meditation by sitting beneath or under a pyramid.

Source

http://spiritual-healingindia.blogspot.com.au/2011/12/sit-for-meditation-after-doing.html