Ruby is a variety of the mineral cornundum and owes its color mainly to the presence of traces of chromium. The mineral corundum is an aluminum oxide. In addition to ruby, the mineral corundum can have many other colors, for example blue (sapphire) and orange-pink (padparadscia).

The name "emerald" derives from the Greek σμάραγδος (smàragdos) and means "green gem".
Its history dates back to Ancient Egypt, where emerald mines were active since 3000 BC.
Cleopatra, the last queen of Egypt, is known for her deep love of emeralds. For the Egyptians, the emerald was a true national symbol.
The emerald was already considered a powerful talisman for fertility, immortality, rejuvenation and spring.