Along with the earrings, Marian sent a card that explained the wonders of niobium, the metallic element from which they're crafted.
Niobium is named for Niobe, the daughter of Tantalus for whom the element just below Niobium is named. Apparently these two elements are very similar, and are often confused. Niobium was named quite late, and is still called by another name by many scientists.
Niobe is one of the most tragic figures in Greek mythology: a mother who brags about her 14 children. Her hubris results in the killing her sons by Apollo and her daughters by Artemis. Homer compared Priam, King of Troy, to Niobe after Priam lost his son Hector. Even with all of my study of the periodic table, I hadn't realized that it commemorated such human tragedy.