Macroscopic Aspects
Macroscopic aspects of nepheline syenite are similar to those of granite. The presence of nepheline and absence of quartz are the fundamental difference. Biotite is generally of low content and the main mafic minerals are clinopyroxene (±) and amphibole (±). The macroscopic colour is grey, being little darker than granite. There is high-grade metamorphic rock originated from nepheline syenite that is characterized by gneiss texture of very rare occurrence. It is called nepheline syenite gneiss or litchfieldite. An example is found at Canaã village, State of Rio de Janeiro, Brazil.
Read more about this topic: Nepheline Syenite
Famous quotes containing the word aspects:
“I suppose an entire cabinet of shells would be an expression of the whole human mind; a Flora of the whole globe would be so likewise, or a history of beasts; or a painting of all the aspects of the clouds. Everything is significant.”
—Ralph Waldo Emerson (1803–1882)