Master Iker:
The jewel bought at auction? Yes. So you noticed? That jewel is not an ordinary gem. I also felt a strong magical power emanating from the jewel, which is why I purchased it in the first place. But did you also perceive that the powers emitted from this jewel have a strong sense of... darkness.
If you absolutely must have this jewel for your research, I'll trade it for something else. But you must first promise me that you will use the dark powers of this jewel responsibly.
If you are like Hardin and his disciples, who were seduced by the powers of darkness and set their hands on forbidden dark magic, I shall never surrender this jewel. So promise me that you'll not use this jewel for evil purposes.
I promise.