Willemite ti'om the Ilimaussaq alkaline Intrusion

• Main Author: John Metcalf- Johansen
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Greenland; Ilimaussaq; Sion
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.609.690; http://www.minersoc.org/pages/Archive-MM/Volume_41/41-317-71.pdf

SUMMARY. During the summer of I967 willcmite was found for the first time in the Ilimaussaq alkaline intru-sion, South Greenland. The willemite occurs in an albitite together with aegirine/acmite, albite, analcime, arfved-sonite, apatite, chkalovite, hemimorphite, microcline, monazite, natrolite, naujakasite, neptunite, sphalerite, and polylithionite. Analytical, optical, and X-ray data were obtained from the willemite. Willemite from a calcite vein at Franklin Furnace, New Jersey, and from a quartz vein at Mussartflt, South Greenland, were also examined. One of the willemite crystals from Ilimaussaq was a trilling on . This is the first time willemite has been found as a trilling. DURING field work in the summer of I967 in the northern part of the Ilimaussaq alkaline intrusion, South Greenland, the writer collected a few samples of an albitite from the slope between Quanit Qaqa and Steenstrups Fjeld. In I97o when the material was fortuitously examined in ultraviolet radiation, discrete crystal aggregates gave off a brilliant blue-green fluorescence, identified as emanating from the s-zinc orthosilicate wiUemite. This is the second discovery of willemite in Greenland, the first being made by Rink and Steenstrup in quartz veins at Mussartfit, Tunugdliarfiq Fjord, Julianehaab district, South