European Journal of Scientific Research (ISSN: 1450 ... - EuroJournals

© European Journal of Scientific Research, Vol 7, No 5, 2005
about 1.8meters and cuts obliquely across the lineation trends in surrounding amphibolites.
There has been studies on muscovite as accessory (minute crystals associate minerals) in rocks
[1,2] but there has been no attempt at analyzing the muscovite books for industrial uses. In both
locations the muscovites are associated with tourmaline and electron microprobe analysis of the
tourmalines indicate that their compositions fall within the dravite-schorl solid solution series
defined by the substitution Mg and �Fe at the Y-site [3]. This paper is an attempt to evaluate the
quality of the muscovite and should serve as a guide to exploration for more raw materials critical
for the industrial take-off of a developing economy.
EXPERIMENTAL
Several samples of muscovite have been chosen from these two pegmatite bodies. These samples
are parts of the study collection of the Natural History Museum, Obafemi Awolowo University,
Ile-Ife Nigeria. The major elements were measured using an using a CAMECA SX 50
electronprobe microanalyser and the mineralogical purity has been established using a Philip
characterized X-ray diffractometer (Ige personal comm.). Five representative samples from the
two pegmatite bodies were selected for PIXE measurement. Three specimens, about 13 mm by
13 mm in size each were taken from each of the five representative muscovite samples and
coated with 5 µg/cm2 to ensure good electrical contact. The coated samples were then mounted
on the wheel for the target sample holders inside the scattering chamber. For the quality control,
the geological standard reference materials GA, DVG and the IAEA SOIL-7 were used. About
350 mg of each of the geological standards were taken and pelletized using the 15 ton Perkins
Elmer pellet machine with a 13 mm die. The pellets were also coated with 5µg/cm2 carbon for
the same purpose and mounted on the same wheel for sample holders together with the coated
muscovite samples inside the scattering chamber.
The muscovite samples coated with thin carbon layers and the coated geological standards were
bombarded with a 1.8 MeV collimated proton beam of diameter 6mm from the 2.5 MV AN –
2000 Van de Graaff accelerator at the Istituto Nazionale di Fisica Nucleare (INFN), Laboratori
Nazionali di Legnaro (LNL), Legnaro (Padova), Italy. A good vacuum of about 4 x 10-6 torr was
maintained in the scattering chamber during measurements. The emitted X-rays were detected
using a 80 mm2 X-ray Si (Li) detector with energy resolution of 160 eV at 5.9 keV. A PC
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