Amethyst forms in volcanic voids over 130 million years, unseen until the first cut reveals violet crystal geometry.
The hexagonal quartz lattice builds atom by atom, iron and aluminum traces painting a violet spectrum from lilac to deep.
At two thousand atmospheres, trace elements transform common silica into crystals refracting the entire purple band.
Without the hollow cavity, crystal points have no room to extend, no facets to catch light — emptiness makes beauty possible.