In Praise of the Striated Cube

Last winter I spent three weeks at the Freiberg cabinet, turning a single cubo-pyritohedron under raking lamplight until I could draw it from memory. The face was not smooth, as the textbooks pretend, but ruled with fine parallel striations that ran true on one face and crosswise on its neighbour. That alternation is not a flaw of growth; it is the crystal confessing its own internal symmetry.

The Lie of the Perfect Solid

We teach pyrite as the model cube, then act surprised when nature delivers something twinned, intergrown, and faintly tarnished to a bruised gold. The iron pyrite cube tells the truth of its lattice better through its imperfections than through any idealised drawing pinned above a lecture bench.

A striation is a fault line in our certainty, not in the crystal.

Set against the slate-grey matrix it grew from, the brass-yellow metal holds its luster for centuries, dimming only at the edges where sulphur slowly turns to that greenish-black streak. To read a habit plate honestly is to accept both the gleam and the tarnish as one continuous fact.