YANTRA

 Literal meaning of Yantra is a machine or a mechanical process. For the management of abstract concepts, it also require a mechanism. Such a mechanism is an abstract form of machine. Yantra is a nucleus of everything visible and conceivable which may be grasped and understood. Depicted by a linked diagram of lines through which visualized energies are realized and concentrated, several such Yantras are described in religious texts.  Sri Yantras is one of the most famous one. People consider it as the Great Yantra. Other lesser yantras like Om yantra, Kali yantra are obviously segments out of the all embracing Sri yantra. It is presumed that Yantras may be formed or created out of several permanent forms and substances. The most important substance is the rock crystal. The philosophical and symbolic significance of this material is particularly because of its being clear, colourless and crystal. It can be shaped so as to focus light at its apex enabling it to become a very good emblem for the all inclusive substance of fundamental reality.  Just as the bright and colourless sunlight is inclusive of all the colours of the spectrum, crystal can also serve as the analogy for the inclusive substance.