Copper turned out to be very easy to find. There was plenty of copper, and Rino decided they did not need to find a new copper vein until the copper bank Noir stumbled upon was depleted.

Under the light, it was easy to find copper because of that orangey tinge on the walls.

"Be careful not to mine up clay. Copper has a more solid feel and is less smooth. Sometimes, it will look diseased with bumps on the rocks instead of just a smooth surface. At the same time, copper can sometimes be green. The colours vary. This bit of copper is fresh, so it is still mostly orangey."

Green?

"Why will it sometimes be green?" Rino asked.

Noir shrugged. In all honesty, this was more of Phil's alley than his. Ace was only good at understanding economy and psychology. The god of landscaping would know more, and all the information he now knew was purely through observations.

Seeing that Noir did not answer, Rino did not press on. However, he was still curious why the metal would change colour. Was it a permanent or a temporary change? Did copper have variants as well?

In any case, Rino would be recording his blacksmithing journey to see if he could find a match in the dwarven archives and understand more. Maybe they would explain why copper was sometimes green and if there was a different use for green copper than orange copper.

Next on the quest list was tin. This metal ore was slightly harder to locate, and Noir walked down the mine shaft twice while sniffing before declaring that this shaft was no good for tin. They found coal and copper easily but no tin.

"Tin is slightly more complicated to mine," Noir explained. "The metal ore is not in its purest form, and often, it is found with impurities."

Rino had no idea what impurities in an ore meant. However, he supposed that might be the case between the orange and green copper ores. Maybe one type of colour meant that it was more metallic than the other?

Noir sniffed and made rounds, walking to the next mining shaft, pawing at random locations, and making minor scratches. Sometimes, he would leave scratch marks on the walls and other times, the stone would dull its claws.

Not knowing any better, Rino could only follow Noir's lead in the mines as they went from shaft to shaft.

"There's a dead-end right ahead," Rino explained as they were heading towards the forked roads of their sixth mine shaft. The roads here were becoming less established, and the rail tracks were incomplete. The last laid track was several hundred meters back, but Noir remained stubborn. 

It should be somewhere around here. Noir wasn't so sure how rare this tin ore was, but according to Phil, it was rather rare and was often found around iron sometimes. The ore was silvery grey without impurities, but those were hard to spot. They often do not exist naturally and had to be extracted from mixed ores that contained iron clumps. Honestly, there were too many brown and black stones in this mine, and each time Noir thought that was tin, it turned out to be something else.

Why was this so hard?

With his paws feeling sore from treading on the rough ground, Noir gave up on walking and hopped onto Rino's shoulder to hitch a hike. However, he remained adamant about the direction they were going.

It was close. Noir could sense it! Despite the excited tail flicks batting on the back of his skull, Rino wasn't sure if this was wise. The mine here wasn't completed for good reasons. Even if tin was located here, they should find another deposit and leave mining this vein to a professional. 

The uncompleted mine shaft got narrower, and Rino found himself having to widen the road if he wanted to fit. Crouching and hunching over to walk in these smaller tunnels was no longer viable. He'd reached his limits, and even Noir was forced to walk in the narrow passages.

There wasn't any light this deep into the cave either because it was too cramped for Rino to properly connect the mana web arrays.

"Come on," Noir urged as Rino crawled into another hole and hit his skull on the protruding rock. "It's close. I can smell it!"

Even with Noir's tiny body, there was still a limit to where he could go in this poorly dug tunnel. Rino followed with great difficulty as the black cat went ahead.

Blasting open a road with dark magic, Ace checked the rocks in the area. It was hard to tell which rocks were what in the dark, even with dark vision enabled. However, Phil's appraisal skill gift to his incarnate proved very useful. At one glance, the god of prayers could tell what kind of ore he was looking at. The tin deposit location was near, but Noir had no idea how to get to it. The vein was buried about fifty metres deep, and no roads were going down.

Pawing at the ground when dark magic could not blast through these tough stones, Ace wondered if this was the end of their ore searching journey.

The delay allowed Rino to widen the tunnel sufficiently to catch up to Noir, who sat there looking at the dead wall ahead.

"What's wrong?" he asked.

The cat's ears were turned back slightly, and the tail was twitchy, occasionally swishing from side to side as he sat there. As a cat lover and stalker for many years in his previous life, Rino understood that Noir was annoyed. That low subconscious meow and half growling sounds was a warning.

Unaware of his incarnate body's instinctive behaviour, Ace simply tapped the stone in front of him with a paw.

"It won't cut this stone blocking my way to the tin."

Rino stopped in front of the stone and pulsed some magic through it. The stone simply absorbed it and remained stubbornly in place. Ah, this was going to be a pain. Rino had no idea what stones these were, but if there were mana emitting crystals, there would be mana absorbing stones.

"I think we have to go around these," he told Noir. "They absorb mana."

Using an area detecting magic to scan the size of this mana absorbing mineral, Noir groaned. It was at least fifteen meters long. They did not really have time to be mining without proper tools.

When Rino heard that it was almost fifteen meters long, he paused. It wasn't convenient to mine this without the help of magic. If anything, he wanted to backtrack the last few hundred meters to properly connect the mana web array. Without proper lighting, it was difficult to mine out sections of this tunnel.

"How far is the tin vein?"

From Noir's current position, it was a steep fall to find the tin vein. Rino calculated the angle of descent he wanted to make to get to the tin deposit. It had to be travel friendly for the miners and spatial minecarts. There was currently no way to build moving platforms like the ones the dwarves built in their library. Moreover, he needed to be careful to not mine too close to the other tunnels. Miscalculating the amount of space needed will result in the tunnels collapsing into each other.

"Can we come back to this later and find iron first?" he asked, hoping to cheer the irritated black cat.

Ace slapped his tail onto the ground twice. "It's also there."

Ah, no wonder the black cat was so irritated. Both iron and tin deposits were in an area that wasn't easy to access. Throughout their mineshaft explorations, Rino never saw any iron ores. The walls were properly mined in many areas, leaving gaping holes sometimes, and he never once questioned what the dwarves were mining. Now, it made more sense. Many things that the dwarves crafted would require iron. It was used to forge things like steel, after all.

There was no questioning it now. They simply had to find a way to get down.

"Let's retrace our steps," Rino offered and carried the grumpy cat in his arms while crawling out.

Noir couldn't complain when he was scooped up, and Rino decided to call their cave exploration activities a day to better prepare for the tin and iron mining session. He might have to ask for special courier delivery. The stone pickaxes that hobgoblins used in Noir Province cut through stone like butter. It worked better than earth magic, and Rino could use a few hundred paws to help him with the tunnel digging.

The only concern he had was if his mana could sustain the mining activities of Kamiya's clan. The killer rabbits built the Nightless Underpass in under a week. Digging a tunnel several meters deep towards the tin and iron deposit should be a breeze for them with proper tools.

Ace sulked. His paw pads were sore, and they had to return empty-handed because of an unexpected roadblock. With only three days to complete this quest, how could Rino be so relaxed?