Abstract

Micro-FTIR (MFTIR) measurements were carried out on the natural recrystallized quartz in Ryoke granites from Mt. Takamiyama. The recrystallized quartz always shows a very strong IR absorption band at 3596 cm (super -1) (2.10 abs. cm (super -1) (normalized absorbance) under unpolarized conditions at room temperature). However, naturally deformed quartz does not show this absorption band, but only a characteristic broad band centred at 3400 cm (super -1) . This shows that the predominant forms of H-related species in the recrystallized quartz are different from those in naturally deformed quartz. The 3596 cm (super -1) band is not affected by room-temperature X-ray irradiation or by annealing at temperatures of up to 600 degrees C, and shows broadening and a positive peak shift with temperature in in situ high temperature measurements. Polarized-MFTIR measurement shows that the band has a strong polarization; the OH dipole is oriented at 35 degrees to the a-axis in the (1010) plane and is isotropically distributed in the (0001) plane. From the stability of the band at high temperatures and against irradiation and its sharpness, the band is considered to be due to the Al(H) type point defect with no alkali which might occupy a structural position in the quartz structure.

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