Crossed polarized light image of melilite in Moiliili lava flow, Moiliili Quarry, Honolulu, O ahu, Hawai i surrounded by matrix of granular nepheline and volcanic glass.
22.
Minerals with the melilite structure may show a cleavage parallel to the ( 001 ) crystallographic directions and may show weaker cleavage perpendicular to this, in the { 110 } directions.
23.
Nyiragongo's lavas are made of melilite nephelinite, an alkali-rich type of volcanic rock whose unusual chemical composition may be a factor in the unusual fluidity of the lavas there.
24.
It occurs with calcite, ettringite, wollastonite, larnite, brownmillerite, gehlenite, diopside, pyrrhotite, grossular, spinel, afwillite, jennite, portlandite, jasmundite, melilite, kalsilite and corundum in the limestone xenoliths.
25.
The presence of the following minerals precludes a rock from being classified as a lamproite : primary plagioclase, melilite, monticellite, kalsilite, nepheline, Na-rich alkali feldspar, sodalite, nosean, hauyne, melanite, schorlomite or kimzeyite.
26.
The most famous of the rocks of Aln�n is the " alnoite ", named from the Island, which is a lamprophyre chiefly composed of biotite or phlogopite and melilite as essential minerals, commonly with olivine, calcite and clinopyroxene.
27.
Sanidine, melanite, hauyne and perovskite are frequent accessory minerals in these rocks, and many of them contain melilite in some quantity, The well-known leucitite of the Capo di Bove, near, Rome, is rich in this mineral, which forms irregular plates, yellow in the hand specimen, enclosing many small rounded crystals of leucite.
28.
Mitchell has suggested that rocks belonging to the " lamprophyre facies " are characterized by the presence of phenocrysts of mica and / or amphibole together with lesser clinopyroxene and / or melilite set in a groundmass which may consist ( either singly or in various combinations ) of plagioclase, alkali feldspar, feldspathoids, carbonate, monticellite, melilite, mica, amphibole, pyroxene, perovskite, Fe-Ti oxides and glass.
29.
Mitchell has suggested that rocks belonging to the " lamprophyre facies " are characterized by the presence of phenocrysts of mica and / or amphibole together with lesser clinopyroxene and / or melilite set in a groundmass which may consist ( either singly or in various combinations ) of plagioclase, alkali feldspar, feldspathoids, carbonate, monticellite, melilite, mica, amphibole, pyroxene, perovskite, Fe-Ti oxides and glass.
