Please note that the label lists only ‘S.W.Africa’ (Namibia) and I’m guessing that it is most likely a Berg Aukus specimen as I have seen this form before from Berg Aukus.
A nice miniature from an old collection.
Ex. Donald Stockton (1929 – 2016), complete with his label.
© Birkhill Minerals
Grootfontein District. Namibia