Nephelinite
（重定向自Olivine nephelinite）
![Nephelinite lava (grey) containing a xenolith of peridotite (yellow), Kaiserstuhl, Germany.](/Images/godic/202501/30/Nephelinit2853.JPG")
![Columnar jointing in melilite-olivine nephelinite from the Southern Balcones volcanic and intrusive rocks, Uvalde County, Texas.](/Images/godic/202501/30/Uvalde_columns2853.jpg")
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite). If olivine is present, the rock may be classified as an olivine nephelinite. Nephelinite is dark in color and may resemble basalt in hand specimen. However, basalt consists mostly of clinopyroxene (augite) and calcic plagioclase.