Mariupolite

Mariupolite

 

an intrusive alkaline rock of the nepheline syenite group, consisting chiefly of albite; the albite in it greatly exceeds the potassic feldspar, which is sometimes completely absent. Mariupolite is characterized by variabilities in mineral composition and structure. In addition to albite (40-70 percent) and nepheline (10-40 percent of the rock), the most frequent minerals in mariupolite are aegirine, lepidomelane, potassic feldspar, sodalite, and cancrinite. Mariupolite makes up masses of alkaline rock that crop out in the southeastern Ukraine north of the city of Zhdanov (the former Mariupol’), after which the rock is named.

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