Note 6 — Chapter VII · CENTRAL CHILE:—STRUCTURE OF THE CORDILLERA.

I here, and elsewhere, call by this name, those feldspathic minerals which cleave like albite: but it now appears (Edin. New Phil. Journal., vol. xxiv, p. 181) that Abich has analysed a mineral from the Cordillera, associated with hornblende and quartz (probably the same rock with that here under discussion), which cleaves like albite, but which is a new and distinct kind, called by him Andesine. It is allied to leucite, with the greater proportion of its potash replaced by lime and soda. This mineral seems scarcely distinguishable from albite, except by analysis.