Name:   Nepheline-Sodalite Syenite

Geologic Name:  Member of White Moutain magma series

Reference: Quinn, Alonzo, Petrology of the alkaline rocks at Red Hill, 
New Hampshire:  Geol. Soc. America Bull., v. 48, p. 384-387, 1937.

Microscopic characters:   Hypautomorphic granular texture.  Lath-shaped
perthite, often with carlsbad twinning, constitutes over half of the slide.
Green amphibole (hastingsite), sodalite and nepheline complete the list
of essential minerals.  Magnetite, apatite, zircon and titanite are the
important accessories.  Some biotite is present as alteration of the 
amphibole.
