Case file · High strangeness
The Klerksdorp spheres
Small grooved spheres from 3-billion-year-old rock mined near Ottosdal were promoted in the 1980s and after as artefacts made by an ancient intelligence.
1984 CE · -26.81, 26.00 · status: explained
The account
Claims that they were perfectly round, impossibly hard or slowly rotating in a museum case circulated in fringe literature. They come from pyrophyllite deposits worked by Wonderstone Ltd.
The sceptical view
Geologists explain them as natural concretions; they are neither perfectly round nor unusually hard. The year is approximate for when the claims spread.