Also, when diaspore was dehydrated, it would turn into corundum and gem cla.s.s corundums were the famous ruby and sapphire. Compared to the former, the latter was even more renowned.

However, it was not the gemstones themselves that excited him.

"What about the residue dug out from the mine?" the prince asked excitedly as he closed the wooden box after a long time.

"Are you asking about... the debris from digging the mine tunnels?"

"That's right, and not just rocks, but mud as well. How did you deal with them?"

"They were all carted out and dumped at the bottom of the mountain." Denver seemed confused about why the prince was interested in this. "Don't worry, Your Highness, all good quality ores were carefully picked out and the remains were either broken in the mining process or of poor quality and can't be polished into gemstones. Moreover, the screening process is done by the most experienced members of my family. They never miss out good quality ores."

"You're wrong." Roland smiled and shook his head. "Those things you dumped... might be the real 'treasure'."

"What?" Denver froze in shock, and the other people also seemed confused. None of them could see the mine residue as treasure.

At the time, Roland find it hard to explain this to them, because in this world even steelmaking was difficult to imagine, let alone pure aluminum extraction.

Diaspore consisted mainly of aluminum oxide and was a by-product of bauxite and its discovery suggested that there was probably a large amount of aluminum in this area. That meant, the mud and rocks dumped by them could be used as raw materials for aluminum extraction. As the most abundant metal element in the earth, aluminum was more common than iron and could practically be found everywhere. Lucia could extract small amounts of aluminum from any rock on the ground, but it was clearly not efficient enough for industrial needs. Only places that were rich in aluminum were worth excavating.

This cave in front of him was one of those places.

Roland called Petrov aside and asked quietly, "How has the Crain Family managed this gem mine in the past 200 years? I mean... how did the past lords pay them?"

"I checked Osmond Ryan's checkbooks, and the payment methods were simple. Every year, the Crain Family could choose a box of second-tier gemstones as their fee in a similar manner as weighing grain," explained Petrov. "This box is as long and wide as one hand and deep as half a hand, and as long as the cover could be closed, they could take as many gemstones as possible. Of course, the rarest gemstones had to be given to the lord."

"That means the two gemstones from their family treasure that he just gave me aren't of the best quality?"

"They really are the best in terms of quality, since he wouldn't dare to deceive you, but you know that gemstones are always more expensive when they're bigger."

"You've also accepted his gifts, correct?" Roland stared at the eldest son of the Honeysuckle Family with great interest.

"Um..." Petrov replied awkwardly, "Yes, Your Highness, I'll give them to you as soon as I get back."

"Keep them, I don't care," said the prince nonchalantly. "I'm just curious about how we can a.s.sure that this payment is accurate. What if the family secretly takes more gemstones during the excavation? Unless we turned their entire house upside down, we wouldn't be able to detect it."

"There're people monitoring the transport and filtering each cart of ore, and even if the Crain Family steals some, they wouldn't make it too obvious—this is a relations.h.i.+p of checks and balances, since the family is afraid of being punished by the lord, while the lord can't find other people who know the mine so well." Petrov paused. "Anyways, if we replace them with our own people, we still can't ensure that no one will steal."

"I see." Roland nodded. "Then let's continue with this practice. But besides the multicolored stones, I also want the rocks and mud that they dig up. When we get back, I'll draft an initial gathering plan for you to follow."

"Your Highness, is the mud... really more valuable than gemstones?"

"It depends on whose hands it falls into," replied the prince.

What's so important about aluminum? It has numerous uses. Having low density and lasting quality, it plays a vital role in the industrial production and is a crucial material used in aviation technology. To be honest, aluminum extraction is extremely difficult now, since the amount of electric power required by the electrolysis equipment is way beyond the capability of City of Neverwinter, but Lucia can offer another solution to this problem and may be able to extract some aluminum first with her ability. Then, weapons that are once impossible in this time period will become a possibility, such as large airs.h.i.+ps.

Roland originally planned to focus excavation on the two iron mines, but now it seemed that he had to adjust his plan.

...

When he returned to the castle after inspecting the two mines and a salt well, the sky was already pitch black.

After dinner, Roland excitedly took out a pen and paper and began drafting a utilization plan for the new resources.

First was the steam engine.

It would drastically increase the efficiency of the draining system in the mines, transportation and brine extraction in salt wells. As the Maple Leaf and Wild Rose families had fallen, he planned to relocate some experienced workers from the North Slope Mine and recruit more workers in the Longsong Area, in order for the two new iron mines to be operated first and their ores could be transported back to the Border Area for refining. Meanwhile, the gem mine's excavation would have to wait until Lucia got to Longsong Stronghold to determine the aluminum content in the mine.

The other focal point was the salt well.

As Roland had predicted, besides using the steam engine to drain water and increase production, he also lacked the vital step to refine the products into pure white salt. Since the mineral contents were quite complex, he decided to take a tube of brine from each well, take them back to the Border Area, and give them to Chief Alchemist Kyle Sichi to find out the specific refining process. After the process was obtained, he could set up a factory on the spot to produce table salt on a large scale.

Of course, the salt industry would be managed exclusively by the City Hall, just like grains. The Elk and Honeysuckle families' salt wells could receive the City of Neverwinter's technological support, but the refined salt they produced must be sold to the City Hall at the set market price, not sold to other buyers in order to gain profit. If he could obtain large amounts of refined salt at a low price, he could undoubtedly create a new commercial path for the City of Neverwinter.

Roland believed that this could all become a reality after he defeated Timothy.