#ServiliasPearl was a pearl given by #JuliusCaesar to his #favourite mistress Servilia. It was described by imperial biographer #Suetonius to be a lone (uniones, meaning "singleton") large #blackPearl worth six million #sesterces (approximately 1.5 billion dollars in 2019 value), making it perhaps the most valuable gem of all time. It may also be the first known individual pearl recorded in human history.