leucite in a sentence

Examples

1. They are black or ashy-grey in color, often vesicular, and may contain many large grey phenocysts of leucite.
2. Minerals such as alkali feldspar, leucite, nepheline, sodalite, phlogopite mica, and apatite may be present in the groundmass.
3. Other localities for this group are at Julianehaab in Greenland with sodalite-syenite; at their margins they contain pseudomorphs after leucite.
4. "' Leucite "'is a twinned, giving rise to twin-lamellae and to striations on the faces.
5. Although these never contain quartz, but feldspar is usually present, though there are certain groups of leucite lavas which are non-feldspathic.
6. Occasionally minerals of the feldspathoid group, such as nepheline, sodalite and leucite, occur, and rocks of this kind are known as phonolitic trachytes.
7. The rocks in which orthoclase ( " or sanidine " ) is present in considerable amount are leucite-trachytes, leucite-phonolites and leucitophvres.
8. The rocks in which orthoclase ( " or sanidine " ) is present in considerable amount are leucite-trachytes, leucite-phonolites and leucitophvres.
9. In some cases they may take other forms, such as nepheline, leucite, and muscovite, but in the great majority of instances they are found as feldspar.
10. Leucite monchiquites are fine-grained dark rocks consisting of olivine, titaniferous augite and iron oxides, with a glassy ground mass in which small rounded crystals of leucite are scattered.