Boron in pegmatite minerals.

In a pa per on the distribution of baron in pegmatite minerals, Ofteda (1964) observed that boron is relatively enriched in rare earth pegmatite minerals, and the enrichment is largely restricted to metamict specimens (Oftedal pp. 223-224). He also noted an uneven distribution in these minerals indicating a connection between the alteration process and the boron enrichment. Most of these minerals, with the exception of gadolinite, contain no atoms for which boron is likely to substitute, and Oftedal suggested a secondary (post metamictization) introduction of boron. The mobility of boron in the crust is high, and the preferential adsorption of boron may be explained by unsatisfied electrostatic charges in the 'amorphous' metamict minerals. The purpose of this note is to bring to attention the possibility of a radiogenic formation of this excess boron.