wulfenite (w. phantom)

A translucent tabular crystal of toffee-brown wulfenite (37 mm on the diagonal), back-lit to exhibit a prominent phantom of darker material at circa 45 degrees to the larger crystal morphology.

Formerly in the collection of Helmut Heuser (Germany).

Bideaux (1990) noted that during crystal growth square tabular crystals of wulfenite often become modified by corner faces and that as the corner faces grow the outline of the crystal becomes octagonal; however, as these faces become still larger, a square tabular habit is restored but at 45 degrees to the original. In some situations, this type of development sequence is recorded by a growth phantom in the core of the crystal.

(not assigned)