Fancy Pink

Pink is the colour that breaks the usual rule. Yellow comes from nitrogen, blue from boron — each a foreign element caught in the lattice. Pink comes from no element at all. It is thought to arise from lattice and plastic deformation: the crystal, squeezed and sheared deep in the earth, was physically distorted, and that distortion bends the way it absorbs light. The colour is written into the structure itself, not into an impurity.

A Type IIa stone

Because no measurable impurity colours it, a pink diamond is overwhelmingly Type IIa — the same exceptionally pure, highly sought-after group that produces the finest colourless stones and sets records at auction. Pink sits among the rarest and most valuable fancy colours of all, and a clean, saturated pink of real intensity is one of the most coveted stones a house can hold.

The Argyle question

For decades, the supply of pink diamonds rested largely on a single source: the Argyle mine in the remote north-west of Australia, which produced the great majority of the world’s pinks. Argyle has now closed. With its richest source exhausted, the supply of natural pink has tightened sharply, and stones that were already rare have become rarer still — a scarcity the market has felt keenly.