When we meditate on other kinds of metals our spiritual approach is different. We can follow the same procedure with copper as we have done with iron, tin and lead. When we meditate on the metallic nature of copper, we become, as it were, merged with, one with copper; our whole soul is permeated with copper, with its colour and consistency, its curiously ribbed surface. In brief, we become wholly identified with our psychic response to the metallity of copper. Then we do not experience a gradual transition towards insensibility, but rather the reverse.  We have the sensation that something floods our whole inner being; our response grows more sensitive. We have a definite impression that when we meditate on copper it pervades our whole being. It radiates from the centre below the heart and is diffused over the whole body. (Steiner 2010:24-5)
STEINER, Rudolf. 2010. True and false paths in spiritual investigation. (Trans.: A. H. Parker) London: Rudolf Steiner Press.