A RHOMBOHEDRAI POTYTTPE OF MOLYBDENITE*

• Main Author: R. J. Traili
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Yellowknife
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.533.9279; http://rruff.info/doclib/cm/vol7/CM7_524.pdf

Rhombohedral molybdenite (molybdenite-3R) has been identified as an accessiory mineral in quartz-feldspar porphyry occurring at the Con mine, Yellowknife, District of Mackenzie. The following observations on the occurrence and origin of the quartz-feldspar porphyry have been taken from Boyle (1961). Irregular dykeJike bodies of quartz-feldspar porphyry are found in the under-ground workings of the Con, Negus and Rycon mines. The porphyries contain phenocrysts of quartz and zoned plagioclase in a groundmass of fine-grained plagioclase, quartz, microcline, muscovite, carbonates and chloritized biotite. Pyrite and pyrrhotite are particularly abundant in the porphyries in the vicinity of the Con mine, and molybdenite is present as disseminated flakes in a few of the bodies. Other accessory minerals include small amounts of apatite, zircon, rutile and epidote. The sulphides appear to be primary constituents, and probably crystallized with the quartz and feldspar, because they fill interstices between these minerals and form along the cleavage planes of biotite.