Urtite

Urtite

 

an alkali intrusive rock containing 80 to 90 percent nepheline. It may also contain as much as 10 percent aegirine or aegirine-augite, as well as admixtures of albite and sphene. Urtite is not widely distributed. It occurs in the form of small, often sheetlike, bodies among other alkali rocks. Urtites from Krasnoiarsk Krai, which are especially rich in nepheline (the Kiia-Shaltyr’ deposit), serve as the primary raw material for the production of aluminum; the by-products of production are used as raw material for cement. Urtite was first discovered in the Lovozero Massif (Luiavr-Urt) on the Kola Peninsula (hence the name).

References in periodicals archive ?
It is located in urtite rock enriched by pyroxene (aegirine-diopside), titanite and fluorapatite.
An absence of these minerals, which are very typical for alkaline pegmatites of the Khibiny massif, combined with the presence of the transition zone between a natrolite body and urtite, demonstrates that we are observing a "pure hydrothermal" body but not a pegmatite.
Urtite is a pale-colored member of the ijolite series that is composed chiefly of nepheline and 0-30% mafic minerals, especially aegirine and apatite (Jackson, 1997).
At Yuksporr, in a veinlet crosscutting urtite, as zones in thomsonite-Ca; associated minerals are: calcite, fluorapophyllite, tobermorite, thaumasite and barite.
Occurrence: In a sodalite-natrolite-calcite veinlet crosscutting urtite.