Firewood was brought in and a fire was lit in a room in the slave yard.

Han Cheng picked up the two smallest pieces of rubble and threw them into the fire.

Under the gaze of everyone, it didn't take long for the two green stones to change color and turn black.

After burning for a while, Han Cheng used a branch to start digging out the two small pieces of burnt black stone.

The stone burned by flames became very brittle, and one of the stones cracked during the scraping process.

Han Cheng put the stick in his hand against the stone that had been dug out and pressed down, breaking it without much effort.

After waiting for a while and letting the broken stones cool down, Han Cheng squatted down, picked up a small piece of burnt black stone, twisted it with his fingers, and it turned into powder.

Looking at the fine soil-like crumbs in his hands, Han Cheng could no longer suppress the smile on his face.

This green stone is malachite. Wherever there is malachite, there must be an open-pit copper mine nearby.

Because malachite is formed gradually from the long-term oxidation of open-air copper mines and the seepage to the outside.

Malachite has always been an important basis for people to find copper mines.

The black powder is oxidized copper. If it is reduced at high temperature using charcoal, copper can be obtained.

But he did not do so because the amount of malachite was too little.

Han Cheng's actions touched the hearts of everyone around him. When he smiled, the people who were watching him also breathed a sigh of relief and became excited.

"A metal can be extracted from this stone. It's not as hard or sharp as iron, but it's just as useful."

Han Cheng announced the good news to the people around him.

Copper is soft and not suitable for making sharp tools, but it is very good for making blunt tools. After all, it is easier to shape and has a toughness that stone does not have.

However, if tin and lead ores could be found and copper tin or copper tin alloy could be refined, this situation could be greatly improved.

Because copper-lead or copper-tin alloy is bronze.

Bronze is hard and can be used to cast sharp weapons and farm tools.

Famous swords in history such as Gan Jiang and Mo Ye are all bronze swords.

Of course, it is not as good as the well-made steel knives of later generations for chopping, but it also directly proves the feasibility of using bronze to make such tools when steel cannot be greatly developed.

Tin ore is relatively easier to deal with because tin ore is generally associated with copper ore.

It makes sense that bronze appeared first and then steel in the history of civilization development, because the melting point of the metal ore required for bronze is much lower than that of steel.

After Han Cheng announced the news, Wu and others were all smiling.

The existence of things like iron knives and axes made them deeply aware of the usefulness of metal tools. Now, hearing the Son of God announce that another kind of metal could be made from this beautiful green stone, how could they not be happy?

As for what Han Cheng said about it not being as good as iron, they simply ignored it. To them, as long as it was metal, it would be fine.

"Where did you get this stone?"

Han Cheng asked the long-legged man standing not far away.

Changtui still looked a little dazed. He had never thought that metal could be extracted from the stone he used as a talisman.

He had seen metal before. The blackened axe carried by the lame carpenter in the tribe was made of metal.

Although he had seen the lame guy carrying a black axe and chopping down trees several times, Long Legs was still surprised by his fast speed.

Now that he knew that the amulet he had been wearing for a long time could refine a kind of metal, how could he not be stunned?

"In...the tribe..."

Long Legs slowly explained the origin of malachite in broken Mandarin.

Han Cheng also slowly figured it out.

On a mountain near the Tengshe tribe, where the grass and trees were sparse, there were some beautiful blue puddles. Changtui picked up a piece of beautiful malachite of the right size there, polished it, tied it with a rope and hung it around his neck as a talisman.

Han Cheng also heard another thing in Changtui's story.

That is, someone in the Tengshe tribe once drank that beautiful water, then had a severe stomachache, and then died.

From then on, they learned that the beautiful water in those pits was not drinkable.

This is the characteristic of primitive times. A lot of knowledge is obtained when people die.

Han Cheng asked Changtui why the man wanted to drink the water in the stone pit. The answer he got was that the water there was as blue as the sky, and some people believed that after drinking it, they could get the blessing of the gods.

Han Cheng couldn't help but sniffle. It's true that ignorance is fearless.

When the rain stopped after nearly a day, it was already dark.

The rain stopped, but because it was already night and the sun had not risen, the air was still very cool, making it most comfortable to sleep at night.

Han Cheng was not very sleepy at this time. On the one hand, he slept too much during the day, and on the other hand, he was thinking about the surprising news he received today.

It is a true portrayal of the news about the copper mine this time.

It was a pleasant surprise and surprise that the copper ore that we had been searching for in vain was right under our noses.

Han Cheng didn't care much about the size of the copper mine there, because according to the current situation of the Qingque tribe, even the smallest copper mine would be enough.

I have to go to the Tengshe tribe’s lair to see what the copper mine is all about, and take a look around to see if I can find any traces of tin mines.

After thinking about the copper mine and things related to copper for a while, Han Cheng made this decision in his heart.

After all, he, as a latecomer in the tribe, is more familiar with these things, so he must go.

And they have to set off as soon as possible. On the one hand, he wants to confirm these things as soon as possible, and on the other hand, Sister Bai Xue is going to give birth soon.

He had to finish this task almost completely before Sister Bai Xue gave birth, and then return to the tribe from there.

No matter what the customs of that era were, Han Cheng would return to the tribe and stay by Bai Xue's side when Bai Xue gave birth.

Because this is the most vulnerable moment for women, and danger is likely to occur. Although Sister Bai Xue is still extremely agile, she has no awareness of being a pregnant woman at all.

Another important reason is that he wants to welcome the birth of his own child.

This is his own flesh and blood, the first child of his future and present generations, and he doesn't want to miss this important moment.