"Synthetic ultramarine, due to its lack of mineral inclusions, boasts a richer tone than its semiprecious predecessor [lapis lazuli]. Traditionalists like Andrew Wyeth insisted on grinding the original, at great personal expense, even with the artificial paint readily available. “A color may be too pure. Modern shades and colors often appear hideous, ironically, because of their extreme purity,” writes Alexander Theroux in his triptych of essays The Primary Colors. “Old-fashioned blue, which had a dash of yellow in it … now seems often incongruous against newer, staring, overly luminous eye-killing shades.” In our pursuit of perfection, of unspoiled coloration, we purged colors of their unique characters.
Even the finest natural ultramarine, ground assiduously by hand, is riddled with odd minerals: calcite, pyrite, augite, mica. These deposits cause the light to be refracted and transmitted in subtly different ways. No two strokes of paint are the same in their fundamental composition. Stand at the right angle and you might catch a quiet glimmer of white or gold, like a prick of light from some distant province of the cosmos."