Stormcoast Black Marble

The most dangerous quarry of the world

Stormcoast Marble is a particularily valuable variant of marble used in construction when the builder wants to draw attention to the wealth of the building owner. It is sourced from Islands along the Stormcoast, earning it the name and justifying the cost.

Features

Marble from the storm coast is rich in bitumen as the main impurity in the limestone, which results in a fine and compact grain in the black base colour. Thin white veins run through the rock, giving it a distinct and easily identifiable look. Apart from this, the stone has all the usual properties marble can offer. It is generally low in internal stress and high in hardness. The rock is also resistant to heat, deforming barely at all even at in hot summer months.
Marble used in construction is generally polished and treated with an acid for recrystallisation. This gives the rock a glossy finish, which accentuates the veins in the rock further. The only real weakness the black marble has is a low resistance to acid, however, given the wealth of the person who can afford to use black marble, buildings are often warded with magic to account for this weakness. Because of this correlation popular belief claims that the black marble is more resistant to acid, despite this being untrue.

Sourcing the Marble

Black Marble of this particular kind only really appears far out in the islands of the Stormcoast. Here the cliffs of the islands often show large deposits of the rare stone, which attracts those that try to harvest it. However, the problematic location makes this job a particularily lethal endeavor. The marble must be struck above sea level and reeled onto strong ships that can withstand the currents and wind, while the people at the cliffside struggle against the almost constant rain and icy conditions.
Once the rock falls the ship must be closeby because of the rope to reel the stone in, but far away enough the rock does not sink it. At the same time, the people working the rocks are in constant danger of slipping and drowning. One mistake can kill yourself and/or your crewmates. In recent years experienced rockhaulers have begun striking deals with the local Merpeople, who can save drowning workers, but they also need to stay away until rescue is needed so they dont accidentaly get hit by falling rocks.
Because of all these factors, the price per square foot of rock is over fifteen times that of regular marble and only the most wealthy can afford it. The people mad or desperate enough to try rockhauling can make quite the profit in short timespans, but ultimately you are gambling with your own and other peoples lives, whenever you attempt a haul.

Aurora Borealis by Frederic Edwin Church