Tourmaline, also known as tourmaline, has a variety of colors and is very beautiful. It can be made into jewelry, but its industrial uses are more extensive.

However, with current technology, tourmaline has more potential to be used as a gemstone than any other use.

At this moment, when the others saw the tourmaline presented by Wei Buzhi, expressions of interest appeared on their faces.

Huo Guang even said, "This is the first time I've seen such a beautiful stone."

Liu Tan looked at him expressionlessly and said, "This can also be considered a type of gemstone, just like crystal and jade, it is very precious."

Everyone was visibly stunned. Wei Buyi reacted quickly and asked, "Is this a new gem?"

Liu Tan sighed and nodded tiredly.

Huo Guang pondered and said, "Your Highness, it seems that we really have to choose those places we visited before."

Because they had coal as an example, they did not doubt Liu Tan's statement at all.

What's more, this stone is indeed very special.

In fact, in Liu Tan's opinion, the quality of this tourmaline is not particularly good. It is not big and its transparency is average. However, natural tourmaline with outstanding color and good transparency is rare.

Those that can be achieved are generally of jewelry grade, and are very precious even in the later era when production was very large.

This piece cannot be classified as tourmaline by any means, but it is indeed tourmaline, and tourmaline can be made lighter in color and more transparent by heat treating dark-colored tourmaline.

Liu Tan picked up the dark green tourmaline. Although its transparency was not very good, it still reflected tiny bits of light under the sunlight, which made his eyes flash involuntarily.

"Forget it, send someone to look at how to mine it. The larger and more transparent the stones are, the better quality they are. Pick out some of the best quality ones from the ones you've collected, and I'll bring them back to Chang'an."

Even though Liu Tan knew that this kind of gem was considered novel and precious these days, it was not easy to open up the market and gain people's acceptance of it at the beginning. Now when people talk about jewelry, the first thing that comes to mind is jade and agate. The burial objects unearthed from the Han Dynasty can also explain a lot.

But it doesn’t matter. Liu Tan is better than others because he has a mother who is the queen.

If there is a title of sales queen these days, the queen would definitely be it.

Apart from those accessories that only the queen could wear, anything that appeared on Chen Ajiao would definitely attract the attention of others and easily create a popular whirlwind among the noble ladies in Chang'an.

The nobles' tendencies will in turn influence the common people. Although this will take time, once tourmaline can be promoted, Liu Tan will have another source of income.

But... he really doesn't lack money now, so can't he just run an industrial zone?

Liu Tan finally gave up on his own site selection and found a few relatively densely packed spots among the ones Huo Guang had asked him to choose. He circled an area and asked cautiously, "Are you sure this time? Are you sure we won't find any more mines?"

Huo Guang laughed out loud without giving any face this time: "Don't worry, Your Highness. I have sent people to carefully survey this area. There is absolutely no..."

At this point, Huo Guang hesitated for a moment: "How about you go and take a look, Your Highness, just in case..."

What if there is something new that they don’t know?

When he said there were no mines, he just meant there were no mines like the kind they know about now.

Liu Tan saw him pause and was about to ask, but he quickly understood what he meant and said bitterly, "Then let's just build it first!"

There are actually many mineral resources that he doesn't know much about, not to mention that even if he digs them out, they may not be useful. Many minerals are only discovered and used when technology reaches a certain level. Since they cannot be discovered now, let those things stay underground.

Liu Tan had given up struggling. He had thought before that there might be minerals in this barren land, but he had not expected that the minerals would be so dense. Even if the land was large enough, there would still be too many.

Seeing Liu Tan's face full of despair, Huo Guang said nothing more, but simply asked, "By the way, does His Majesty agree that Your Highness will increase his private army?"

Liu Tan slapped his forehead and said, "I did mention this, but I've been so busy these past few days that I forgot about it."

Huo Guang quickly asked, "How much?"

"Five thousand." Liu Tan hesitated. "But... isn't that a bit too many people? Should we raise fewer?"

This number may not sound like much compared to the hundreds of thousands of troops involved in a campaign, but in fact, with these troops, as long as Liu Tan has any second thoughts, they can directly attack Chang'an.

Liu Tan was still a little worried. There were too many people, and he didn't need so many guards. To be honest, these guards were mainly guarding against the Huns. In the Northern Border Kingdom, as long as they knew that the minerals belonged to the King of the Northern Border and he didn't want to die, no one would try to covet them. The only thing they needed to worry about was the Huns.

But if the Huns come, the army of the Northern Border Kingdom will resist and counterattack. Yes, the soldiers under Sang Qian are used to do this.

Huo Guang was also shocked by this number and looked at Liu Tan deeply. If Liu Tan had not already become the King of the Northern Territory and was not reluctant to leave the Northern Territory, he would even doubt whether Liu Tan was the emperor's favorite heir and whether the position of the crown prince would be in danger.

He thought for a moment and said, "Let's raise 3,000 first. That's enough. If we discover another mine in the future..."

Liu Tan jumped up and asked, "Do you think I live in a mine?"

Huo Guang thought that if you don't live in the mine, the mine will follow you.

But he didn't say anything, letting Liu Tan angrily write a handwritten order. After he finished writing, Huo Guang asked, "What are you going to do about Xi'an Yang County?"

Liu Tan said casually, "Let Sang Qian serve as the acting county governor first. The people sent by the emperor are already on their way. When they arrive, give them a welcome gift."

Huo Guang asked cautiously, "What's the gift?"

Liu Tan smiled: "Of course it's the exam."

Huo Guang thought it was bad luck for them.

But he also had to admit that Liu Tan's method was really simple and effective, and it could test everyone's bottom line to the maximum extent. People who couldn't even reach this bottom line had to take remedial lessons first, no matter how capable they were!

A smart person who doesn’t know the rules is more deadly than a stupid person!

Huo Guang calculated and said, "They haven't arrived yet. Your Highness will probably leave soon. Then Your Highness will have to leave the test paper behind."

Liu Tan looked up and asked, "Aren't you going back with me?"

Huo Guang shook his head: "If I leave too, I'm afraid the Northern Border will be in chaos."

Liu Tan laughed and said, "Not really. Wasn't everything fine before the Northern Border Kingdom existed? Everything is still in its infancy now, and we can just handle it based on our past experience. If you don't go back this year, you might get busier and busier, and you might not even have the chance to go back."

Huo Guang said calmly, "I have no worries."

Liu Tan asked, "Where are your nephews and nieces? Don't you care about them?"

Huo Guang hesitated for a moment, and finally whispered, "They... have their own paths to follow. Even if I can control them, it's limited."

Liu Tan's eyes widened. "You are their uncle, so it's only natural for you to adopt them. How can there be a limit?"

Huo Guang said, "Princess Changxin is taking care of them."

Liu Tan said, "The Princess may take care of them, but the guidance of a father and brother is indispensable, especially for the young master. If it weren't for the bad weather in the Northern Territory, it wouldn't be a big deal if you brought them here."

But it is not possible now. Huo Xian's sudden death has left Liu Tan with a psychological trauma. Huo Qubing only has one son and one daughter left, and they are still young. If they are taken to the Northern Border Kingdom and then die, he will not be able to forgive himself even if he kneels in front of Huo Qubing's tomb for a long time.

Huo Guang's eyes lit up and he began to consider the matter seriously.

However, he was still a little worried and asked, "If I leave, who will assess the people sent by Your Majesty?"

"Jiang Chong," Liu Tan said cheerfully, "he has no relatives in Chang'an, so there's nothing for him to do if he goes back. Let him stay. Oh, Sang Qian can't go back either, as he has to manage Xi'an Yang Commandery. The rest of you can all go back to Chang'an."

Huo Guang thought about it and felt that Jiang Chong was a suitable person. Even though he looked down on the means by which Jiang Chong came to power, he had to admit that he was a capable person. As long as he did not go astray, everything would be much better.

Huo Guang asked, "What will Your Highness take with you this time? You can't return empty-handed."

Before coming here, everyone's impression of the Northern Kingdom was that it was poor, desolate, and lacked people.

Now if the truth is known, everyone’s impression of the Northern Kingdom may become – mines everywhere.

Liu Tan thought for a moment and said, "The gold for offering sacrifices must be sufficient and of good quality. You should know how many people have fallen into this trap."

Huo Guang chuckled and said bluntly, "Your Highness should know why they stumbled. Whoever stumbled here was definitely not Your Highness."

Liu Tan thought about it and agreed. The essence of Liu Che's plan was to centralize power and save money, but he would never betray his son.

Liu Tan shrugged. "Anyway, just keep this in mind. Then... have Wei Buyi set aside two pieces of fine agate. Miao Rui, arrange for the craftsmen. I want to carve a dragon and phoenix agate cup and ornaments. I'll give them the designs. Oh, and get some gold from the treasury. Um, make two ornaments and a set of horse ornaments."

After a pause, Liu Tan added, "I heard that Lu Xuan has already sent the celestial horse to Chang'an. It would be a good idea to find a set of horse ornaments for Father."

Speaking of this, Liu Tan felt a little complicated. Lu Xuan was in Chang'an now, and it seemed that Zhengdan would stay there as well. Maybe the two of them would meet again.

Until now, he has been very curious about the relationship between Lu Xuan and Liu Che. Thinking about how hard Lu Xuan worked to conquer Dayuan and personally sent the Tianma over, it is hard to say whether he found an excuse to come to Chang'an earlier. Looking at it this way... it always seems even more strange.

Liu Tan dismissed this thought and continued, "By the way, have Wei Buyi bring over the larger pieces of tourmaline he's mined, and process the less attractive ones..."

Having said this, he suddenly got stuck.

Tourmaline can be processed, and he also knows that it requires heat treatment, but how exactly is this heat treatment done?