Mother Rock

Mountains fall at the hands of Clan Antipater as they mine the valuables buried within. These dwarves came during the First Exodus, when the elves and dwarves left their homeworld and entered the realm of Humans. Clan Antipater carried with them the sacred Mother Rock and from this obsidian obelisk grew all the earth's ore and gems which started the Age of Metal.
The Mother Rock no longer creates ore but it has taken on a new life: granting resistances to those who touch it and survive the trials it demands of them. Upon touching it, the person's soul is sucked into the Rock and taken to a private demiplane and must overcome a challenge based on a past failing. These challenges can sometimes seem to last years but only an instant passes on the person's homeplane. Even if the person overcomes their challenge, the time change can cause temporary madness.
Due to the connection to the Elven and Dwarven homeworld, those races receive enhanced rewards. Routine caravans enter the city from distant reaches and bolster the economy.
A small pool of water surround the Mother Rock. It too appears to be pure black and has resisted all attempts to drink or remove the water. Rocks thrown in don't make a ripple and simply disappear. Many who stare into the deep black of the pool lose themselves and become obsessive about digging deeper into the earth. Visions of rich deposits of rare metals fill their head. Many disappear into the mountains and others begin digging in the middle of city. No deposits have ever been returned to the city despite the hundreds who go missing.
This is the only region that mints electrum coins, a mix of gold and silver. It represents the variety of metals created by the Mother Rock and remains the most used coin of the area.
Would you touch the Mother Rock? Let me know in the comments!

Clan Antipater by Thirsty Bard

Filler spot - environment: obelisk - RPG Stock Art by Dean Spencer