Due to the wide variance of characteristics that are associated with tuffs, the rocks are often classified in a number of ways in order to more specifically identify the material. Tuffs may, for instance, be described as crystal, lithic, or vitric, depending on the general nature of the material of which they are primarily comprised. The rocks are also sometimes described more specifically based upon the type of lava from which they formed or a specific substance which dominates their makeup. Among the most common of the tuffs is a reddish-brown andesitic tuff, which can be found along the Cordilleras and Andes mountain chains as well as in Japan, New Zealand, the West Indies, and a number of other locales.