Astronomite

Astronomite is said to be the rarest of the siltstones, discovered by local prospector, J. Pas, in 2002. It is an indurated very fine grained, dark chocolate brown siltstone. Within this are numerous and irregularly spaced pale yellowish cream coloured orbicules 1-10mm in diameter. A close study of the orbicules show them as concentric ferruginous siltstone rings, progressing from an indistinct pale yellowish cream coloured centre, to a broad light banded pink or orange zone, and finally a thin but distinct cream coloured ring.