A precious stone of a fine blue color. It has been used in jewellery and for a variety of decorative purposes. A spectacular example is in the columns of st. Isaac's of st. Petersburg. Lapis was ground up to make up the pigment called ultramarine blue. This colour was the most expensive item in mediaeval and early modern european painting, in part for the fact that it was for centuries mined only in the mountains of persia (now afghanistan). It has long been replaced in paint pigments by an artificial chemical product.