An hour later, in a corner of the inn's main hall in Cape City, Pan Long set a glass bottle containing the Inner Core on the table.
Thanks to Zhao Sheng and Wen Chao, the Nine Provinces World had long since discovered glass and learned to make it. But the process for making colorless glass was complicated, and neither man knew how. Unless a spell was used to purify and decolor it, the Nine Provinces World could produce only traditional green glass.
The bottle Pan Long brought out, however, was colorless. Strictly speaking, it was Quartz Glass, made by melting and reshaping pure quartz sand—or simply powdered crystal—at high temperatures.
It was costly, but still cheaper than colorless glass purified with a spell.
Pan Long had once considered working out how to make colorless glass. He vaguely remembered that ordinary glass was green because it contained ferrous ions. Add the right amount of manganese dioxide, and the green ferrous ions could be converted into yellow ferric ions. If the proportions of purple manganese ions and yellow ferric ions were right, the result would be colorless glass.
...Of course, that kind of "colorless glass" was only nearly colorless, nowhere near the true clarity of Quartz Glass. But the difference in cost was enough to turn it into a gold mine that raked in riches by the day.
As for how to make it work, Pan Long would need to build a research institute, set up a few experimental kilns, and feel his way forward...
Wu Jixing, Sun Qiongyu, Ding Laoheng, and Song Xiaoha all stared wide-eyed at the Inner Core in the bottle, their faces full of curiosity. Pan Long had bound it with True Qi so it could not give off its Evil Aura.
"Is that... the Snake Demon's Inner