Once asked how many hours a week he worked, Chan responded, "When you love someone, do you say that you are in a relationship for three hours a day? If I only work according to a certain schedule, I would be like any other worker. I am in love. I'm forever in a romantic relationship with gems."

The cover of the new book features a special piece of his, The Wallace Cut, made with an "illusionary" carving technique combining cameo, intaglio and gem faceting.

"On the front, you can see five faces, but actually I only carved one face on the back of the stone," Chan told the audience at the museum. "The four more faces you see are actually the result of reflections that were created by precise calculations and faceting."

"It was reverse thinking combined with reverse carving motion," he explained. "What you see on the right I actually carved on the left and what you see that is deep inside the stone was actually carved shallowly."

It took Chan six months to develop the tools for the technique and two and a half years to master them. The whole process was done in water because it generated high heat that could damage the stone.