They moved in on the gallium arsenide immediately, mined it out, and within weeks of completely exhausting the supply they pulled out of Afghanistan.
“Russian mineralogists discovered a major deposit of gallium arsenide in a mountain North of Kabul. Within 6 months the Red Army was inside Afghanistan “helping the regime”.
To the best of my knowledge, gallium arsenide does not occur naturally.
The Russkies might have discovered some major source of a gallium ore, but it almost certainly wasn’t gallium arsenide.
What is the source for this information?
I think this must have been something else. Gallium arsenide is a semiconductor, but apparently it does not occur as a natural mineral.