A suite of volcanic rocks from south-west Uganda containing kalsilite (a polymorph of KAlSiO4)

Arthur Holmes
1942 Mineralogical Magazine and Journal of the Mineralogical Society  
During the last few years large collections of rock specimens from the Toro-Ankole volcanic fields, east and south-east of Ruwenzori, have been sent to Durham by the Geological Survey of Uganda for petrological investigation. The specimens recently studied include representatives of a suite of highly potassic ultrabasic lavas. Some of these resemble melanocratic olivine-nephelinites or olivine-rich ankaratrites, but the nepheline-like felspathoid which they contain, instead of being nepheline,
more » ... f being nepheline, is a polymorph of KAlSiO4. For chemical reasons this mineral was at first thought to be kaliophilite. Other types, closely related, contain leucite, biotite, or melilite, in addition to the supposed kaliophilite.
doi:10.1180/minmag.1942.026.177.01 fatcat:qogizucyxjeo7dgl3ub6ex6m34