Lin Mu remembered reading about this kind of rock in the Memoirs of the Lost immortal. The man had also encountered it before and was actually blocked by it. That was one of the instances when he had been trapped.
He was exploring the depths of volcanic tunnels and it had collapsed, trapping him inside. On one side was fuming magma and on the other side was the Earthen Depths Obsidian.
At that time the Lost Immortal was at the Dao Shell realm. He could not go through the magma as he did not have any spirit tool or skill that would be able to resist its heat and breaking through the Earthen Depths Obsidian was also not an option.
The man was trapped in there for over a year before he managed to escape. He had suffered a lot during that time and had grown weary. But even then he did not manage to break through the Earthen Depths obsidian.
The only reason why he had managed to escape was that there was an earthquake and the magma that blocked his path was drained away. Once he had managed to escape from there though, the lost immortal swore to find a way to escape from that kind of situation in the future.
He practiced defensive Qi skills that were able to bear great heat and also learned about how to break the Earthen Depths Obsidian. This material was actually a mineral that was formed deep in the earth.
It was formed in areas where there was magma and was tempered by heat. It was said that the original minerals that it was formed from were melted and cooled over and over again, till a smooth surface like this was formed.
Earthen Depths obsidian was naturally hard and if a shard of it was broken, it would have an incredibly sharp edge. It was one of the best materials to make pure refinement type of spirit weapons from.
Though the disadvantage of it was that it could not bear formations as much as other materials. Thus, it could not be used for the hybrid type spirit tools either. They could be used for armor too, but that was quite rare, as molding the Earthen Depths Obsidian was not easy.
Jing Luo had heard what Lin Mu had said and was interested in it. He had not learned about this before and wanted to know more.
"You know what this is?" Jing Luo questioned.
"Yes, it's called as Earthen Depths Obsidian and is a hard mineral." Lin Mu spoke before explaining more of the properties of the material to Jing Luo.
Jing Luo being a weapon refiner, immediately assimilated this information and his mind came up with different ways to use it automatically. But this also let him understand how difficult it would be to get past the wall.
"If you know all this, then you should know how to get past it too right?" Jing Luo questioned.
"Yes… while the Earthen Depths Obsidian is quite hard to break, it is also brittle under certain conditions. It is very durable against direct attacks and even Qi skills, but what it can't bear for long is… vibrations." Lin Mu answered.
"Vibrations?" Jing Luo repeated.
"Yes… and I think I also know why there are these small cracks in it now." Lin Mu continued.
"Why?" Jing Luo asked.
"The same thing, vibrations. I'm guessing upon my breakthrough all spirit Qi of this minor plane was resonating. The one in the sky turned into rain but the one in the earth did not have a way to escape.
But this resonance still permeated and caused the spirit Qi beyond the Earthen Depths Obsidian to resonate in response as well. This translated it into vibrations which then caused the cracks in the Earthen Depths Obsidian.
But of course, these vibrations were not strong enough to fully break this wall of Earthen Depths Obsidian as it was caused by the resonance of the spirit Qi. Plus, once the small cracks were created, the spirit Qi could very well escape from there.
This reduced the pressure on the Earthen Depths Obsidian and thus prevented it from cracking even further. In a way it was a self preservative function, one could say." Lin Mu explained.
Jing Luo listened to the entire explanation and nodded his head.
"So we break it with the same method?" Jing Luo asked.
"Yup. Let's see if we can do it." Lin Mu replied and was about to do it when he was interrupted.
"You do know you have a much simpler method right?" Xukong suddenly spoke.
"Huh?" Lin Mu was stunned.
"Just use meld." Xukong reminded.
"Uh… oh right. How did I forget that?" Lin Mu wondered.
"You got engrossed in new information once again… learning it," Xukong replied in a knowing tone.
"Ah, haha…" Lin Mu chuckled lightly.
"Though if you don't want to reveal it right now, you can try using the method you were gonna use," Xukong added.
"Yeah, I'll do that." Lin Mu spoke.
"Is everything alright?" Jing Luo asked seeing that Lin Mu had suddenly stopped.
"No, nothing. I was just thinking something." Lin Mu gave an excuse and placed his palm on the wall.
He channeled some spirit Qi from his meridians and let it reach his palms. From there he coated the entire palm and caused the spirit Qi to vibrate.
At first, there was no response and nothing happened. There was no sound, no movement. But as a minute passed and the vibrations got stronger, some effect could be seen.
~Humm~
The walls could be seen trembling slightly. After five minutes passed though, another noise was heard.
~CRACK~
Jing Luo saw that a thin hair like crack had appeared on the wall.
"It's working! It's working!" Jing Luo spoke excitedly.
But Lin Mu on the other hand was underwhelmed.
'This… is not efficient at all.' Lin Mu thought to himself.
~Sigh~
"Why did you stop?" Jing Luo asked seeing Lin Mu lift his hand.
