1. Forty-Sixth Rochester Mineralogical Symposium: Contributed Papers in Specimen Mineralogy—Part 2.
- Subjects
- *
MINERALOGY , *THERMOCHRONOMETRY , *PHYSIOGRAPHIC provinces , *MINERALS , *GEOLOGICAL time scales , *PLAGIOCLASE , *QUARTZ , *GARNET - Abstract
Heavy mineral separation reveals the presence of garnet-group minerals and magnetite as well as native gold. Magnetite crystals display the same variability in transport indicators as garnet, and there is a notable decrease in the size of individual crystals and the proportion of magnetite between samples relative to their downstream position. Crystals of smoky quartz and amazonite are present as well as a number of accessory minerals, including several beryllium mineral species. The single-crystal diffraction data of eight plutonic labradorite crystals and one metamorphic labradorite crystal show that they all have the incommensurately modulated structures, characterized by the satellite reflections ( I e i -reflections), which cannot be indexed by integer Miller indices. [Extracted from the article]
- Published
- 2020
- Full Text
- View/download PDF