[wideminded]

Russian mineralogists discovered a major deposit of gallium arsenide in a mountain North of Kabul.

I think this must have been something else. Gallium arsenide is a semiconductor, but apparently it does not occur as a natural mineral.

[muawiyah]

Could very well be. On the other hand gallium itself never appears free in nature but is always mixed up with other materials. Arsenic has its own stable forms. At the same time both substances are reported to be found in lead formations, zinc formations, etc.

I'm going on little more than the brief story that appeared in Science Magazine at the time.

It struck me as important since there were few major sources of gallium back then.