'Zafiro' (Spanish for sapphire) is a blue, aluminum-oxide composite and a variety of corundum. It is often used to graze diamonds due to its extraordinary hardness. The composer drew inspiration from one sapphire stone in particular: the Star of India. According to the National Museum of Natural History, "at 563 carats, the Star of India is the world's largest gem-quality blue star sapphire. Some two billion years old, it is also one of the most well-known objects in the world. Rutile, a mineral in the Star of India, gives the gem its milky quality and star effect.

Tiny fibers of rutile in a three-fold pattern reflect incoming light in the star pattern. This effect, called asterism, makes this gem a true star." Abruptly opening with a variation of the central figure, Zafiro has been designed to feature #G A #C A across a modal spectrum from beginning to end. Harmonies derived from the asymmetric division of the scale are utilized to give the piece its blue and solemn nature. Violin techniques such as ponticello and flautato help illustrate the majestic and starry-like essence of the gem. Finally, the piece is full of subito dynamics and tempo changes that mimic the reflexes and highlights in the jewel.