In a secret room.

Yang Xuan sat on the ground, holding the colorless stone in his hand. His face was calm and seemed calm. However, at the moment, he was already stormy in his heart.

In his mind detection, he found that the transparent stone the size of a baby's fist contained a large amount of aura, and the density was unparalleled.

A large amount of aura has gathered and has been transformed from gaseous to liquid. Every drop of aura is transparent and crystal, emitting beautiful brilliance.

Hundreds of millions of drops or even more of liquid aura form a vast ocean, causing huge waves from time to time.

The surprise in Yang Xuan's heart was unspeakable.

Because he found that these auras could be absorbed by him.

In the treasure house, he inadvertently absorbed a trace of aura, which made the six cyclones in his body grow by one point. It can be seen how amazing the aura content in the stone is.

When Yang Xuan suppressed the ecstasy in his heart, he calmed down his mind and began to practice with his mind as a bridge.

At the next moment, the huge aura surged out of the stone, and frantically poured into his body and into the six cyclones.

Both physically and mentally smooth, relaxed and happy!

For a moment, Yang Xuan felt like a tired traveler, soaking in a hot spring; It's like a long dry land, ushering in a sweet dew and restoring vitality.

That comfortable feeling, unspeakable, almost made him moan.

Aura poured in, and the cyclone grew up at a speed visible to the naked eye.

One, two, three

Time passes slowly, sunrise and sunset! Yang Xuan completely fell into cultivation and didn't ask about foreign affairs.

In this way, Yang Xuan sat in this secret room for 13 days. Six huge cyclones in his body finally saturated and automatically stopped absorbing the aura in the stone.

In the void, the golden lightning appeared again without accident.

Yang Xuan was ecstatic. After a short time, he broke through again. All this is the effect of the colorless and transparent stone.

The seven golden dragons danced wildly and roared at Yang Xuan.

The energy of destroying heaven and earth overflows like the destruction and rebirth of the metaphysical universe.

"Boom!" once again experienced the test of the golden lightning dragon. The cyclone in Yang Xuan's Dantian burst open, and seven brand-new cyclones appeared in Yang Xuan's Dantian.

Gas refining seventh floor!

After a short time, he broke through again!

Yang Xuan opened his eyes, shining like a sharp sword, piercing the space.

He felt the great and unparalleled power filling his body. With a little fist, the strong wind overflowed. It seemed that even space could be crushed. Every move was full of great power.

"Come out!" Yang Xuan drank softly.

As Yang Xuan stopped drinking, a fire dragon about a foot long appeared behind him out of thin air, opening its teeth and claws, emitting boundless power and heat.

"Fire dragon skill!" Yang Xuan spit out a name.

"High!" the fire dragon roared up to the sky, and the huge sound waves scattered out through the secret room. It was so powerful that the surrounding birds and animals trembled and knelt down on the ground.

Ha ha, Yang Xuan laughed.

After he refined Qi for seven layers, he had a new understanding of the use of Reiki.

This fire dragon is his new application of flame art. It forms a fire dragon with boundless flame, which condenses the power of flame and has the power to burn all things.

Previously, although his flame was powerful, it was scattered but not condensed, and the range was too huge, which virtually dispersed the power of the flame. Now, he formed the flame into a fire dragon, just as he formed the gold aura into a sharp blade, making the power more concentrated and condensed.

Moreover, the formed fire dragon is completely controlled by his mind, large or small, extremely flexible, changeable and powerful.

With a move of thought, the fire dragon danced around Yang Xuan, making Yang Xuan look like a God, with amazing power.

After playing for a while, Yang Xuan's idea moved again. The fire dragon turned into a little fire and disappeared in the air.

Yang Xuan felt the change of his body and felt full of strength.

When he was refining five layers of Qi, his strength was equal to that of the eight layers of inner strength, and the sixth layer was equivalent to the nine layers of the martial arts. Now, seven cyclones have been formed in his body, which may be almost the same as that of the ten layers of inner strength.

But he didn't really fight with the master of inner strength, and Yang Xuan just guessed like this.

However, with his powerful Taoism, he will never fear anyone.

This is power!

When his strength reaches a certain level, his heart becomes strong.

Then he looked at the colorless stone in his hand and fell into meditation.

After 13 days of absorption, the colorless transparent stone obviously felt much smaller. I think it was because Yang Xuan absorbed a lot of aura.

However, what Yang Xuan cares about is, what is this transparent stone? Why does it contain such a huge aura reserve?

With such doubts, after he left the customs, he came to the family library.

After presenting the token, he was not obstructed, and entered the library in the eager and awe of several guards.

In the huge space, rows of bookshelves are neatly arranged, and countless books are neatly placed on each bookshelf.

According to a rough estimate, there are hundreds of thousands of books in the whole library.

multitude! This is a collection made by a family for hundreds of years. It can never be achieved overnight.

Yang Xuan looked carefully and saw that labels were pasted on each bookshelf. They were classified and uniform. It was very convenient to find them.

Among them, there are skill books, martial arts books, as well as the cultivation experience of senior experts, as well as mainland history, celebrity biographies, anecdotes and so on.

These are not Yang Xuan's goals, especially those martial arts and skills. They are extremely precious in the eyes of others, but for Yang Xuan, abandonment is like my shoes, which is not worth mentioning.

For these books, Yang Xuan walked by without looking at them and went straight to his goal.

This is a huge bookshelf covered with dust. It can be seen that no one has read the books on it for a long time. There is a label on the bookshelf with three big words of mineral resources.

Yang Xuan looked carefully. There were many books on the shelf, all of which introduced various minerals. Yang Xuanxin took out a book.

The title of the book is "geography of Yan state".

When you open it, it is a book about the geography of Yan country, which explains where there are minerals and how the reserves are, in detail.

Yang Xuan put the book back on the shelf and took out another one. It was copper smelting.

Yang Xuan drew several books on minerals in a row. However, he had to calm down and consult them one by one.

This is a look for many days.

Fortunately, Yang Qingshan has long ordered that there is no limit on the time for Yang Xuan to enter the library. Moreover, there are people delivering meals every day, so there is no need to go out for dinner.

However, in a short time, he has read a lot of books and books on minerals, but none of them mentioned the transparent stone.

At this time, what he held in his hand was a mineral overview.

With his cultivation at this time, even a glance of ten lines is not enough to describe his reading speed. More than a dozen pages have been turned over when the pages clatter.

Moreover, his head is clear, his eyes are clear, and he never forgets. These knowledge are transformed into small light spots and stored in his brain.

"Well, smelting and plating zinc ore on the surface of iron can make iron rust free for a hundred years! Isn't this the galvanizing technology?" Yang Xuan said to himself.

From the earth, although he doesn't know much about this knowledge, he has heard of some terms.

For example, the galvanizing technology mentioned in the book he is reading now has been widely used on the earth in previous generations. How can he know.

Through reading during this period, he broadened his horizons, but he still made no progress on the colorless and transparent stone.

After reading this book, he drew out another book. When he saw it, it turned out to be a collection of different fires in heaven and earth, but it talked about several rare flames in heaven and earth.

After turning over, he still got nothing. Yang Xuan frowned and said nothing. He was still patient and wanted to check the next one. This was also his character. He recognized a goal and would never change.

Suddenly, due to the slight shaking of the bookshelf, a book fell from the top of the bookshelf. It was covered with dust and even spiders. It looked really shabby.

Yang Xuan picked it up and patted the dust on it. He wanted to see what the book was, but found that there was no name at all. When I opened it, I found that it was a mining diary and experience written by disciples of unknown generation.

Yang Xuan flipped through it. Suddenly, a record came into his eyes.

"Today, I went deep into an unknown cave in Milian Valley and found no trace of dark feather iron ore, but I found a colorless and transparent stone, which is very beautiful, so I took out two pieces and kept them as a souvenir!"

Yang Xuan was overjoyed. He finally found the record about this stone.

Surprised, he quickly continued to watch.

But for a long time, the unknown elder recorded that he was looking for various minerals, but he didn't mention the transparent stone.

Fortunately, this diary is very thick. Although the record is messy, it is also very detailed. It has been turned over for a long time. Yang Xuan found the record about the transparent stone.

"After sorting out the ore, I found two colorless and transparent stones, so I studied them. First, I checked the records of my ancestors and found nothing. Then I studied them carefully and found that they were useless stones without any metal components. However, the stone was transparent and clear. Take it back to feng'er and put it in the box!"

Yang Xuan turned the diary again until the whole diary was turned over. He never found even the slightest record about the stone.

It seems that this kind of stone is not known by outsiders.

It's not surprising that the world is so big that no one dares to say that he must know everything in the world.

Although he didn't understand what the stone was, Yang Xuan was still very happy because he got a more important message from it, that is, Millian valley.

According to the records of the elder disciple, there are a large number of such stones in an unknown cave called Milian valley.

Where is Mirian Valley?

Yang Xuan went straight to the continental geographic library.