The Case Files of Jeweler Richard (Manga) Vol. 2

After helping out the impossibly elegant Englishman Richard Ranasinghe de Vulpian, Seigi accepts a job in Richard's jewelry store. One day, Takatsuki, a flashy-looking host, comes in looking for something to impress his clients. Takatsuki's eyes light on an amethyst, at which point Richard relates to him the legend behind the stone. What is the jewel's story, and how does it affect the haughty host's decision?