A crystallographic approach to the orb of the New York Salvator Mundi

The New York Salvator Mundi (NYSM) is a painting created around 1500 that depicts Jesus blessing an orb cradled in his left hand, symbolizing the world under his control. The painting, rediscovered in 2005, was restored and, amid some controversy, attributed to Leonardo da Vinci. Like other images of the Salvator Mundi, the orb is a transparent sphere, whose optical distortions pose significant pictorial challenges. Unlike the others, in this painting, the artist surprisingly stained the divine orb with tiny, millimeter-sized speckles. Our crystallographic and mineralogical study reveals that the NYSM contains no significant optical errors and that these tiny structures are anisotropic fluid inclusions, suggesting that the painter intended to depict the divine orb as made of rock crystal.