Nomenclature and Petrography of Leucite-Bearing Rocks

Abstract

The nomenclature of the leucite-bearing rocks is rather complex as there was a tendency to assign local names to rocks having slightly different mineralogy. Whenever possible, a simplified nomenclature, based on the mineral components rather than the local names, is used here. Because of the complex old terminology a discussion of old and new nomenclature is necessary. The modal and mineralogical compositions of various leucite-bearing rocks are summarized in Table 2.1. In the following pages they are described in the order of increasing number of main constituent minerals.