8-sphene. FIG. 1. NORMAL GRANITOID VARIETY OF SYENITE. X 18. b-biotite. c-calcite m-microcline. e-elæolite. p-pyroxene. can-granular cancrinite. Remainder of slide mainly microcline and other felspars. G. S. I. Calcutta. A. M. Heron, Photos. FIG. 2. GRANITOID VARIETY OF SYENITE, UNDER CROSSED NICOLS. showing phenocrysts of elæolite E in mosaic of microcline, plagioclase and orthoclase, with amphibole (dark.) FIG. 1. GRANITOID VARIETY OF SYENITE, WITH MORE FERROMAGNESIAN MINERALS A-amphibole. E-elæolite. THAN IS USUAL. P-pyroxene. S-sphene. a-apatite. So-sodalite. E-elæolite. G. S. I. Calcutta. FIG. 2. BANDED TYPE OF SYENITE. So-sodalite. S-sphene. pale portion of slide-felspars, dark portion aggregate of biotite and pyroxene. |