a fine-grained, dark rock of volcanic origin, essentially a basalt containing nepheline but no feldspar and little or no olivine.
Origin of nephelinite
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Examples from the Web for nephelinite
Historical Examples of nephelinite
They are chiefly leucite and nepheline rocks, such as leucitite, leucitophyre and nephelinite, but basalt and trachyte also occur.
a fine-grained basic laval rock consisting of pyroxene and nepheline
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