Oluan Cloudstone

[Prompt: a resource that provides fuel or power]
There is a substance on Olua with great potential: a kind of "stone" that arises from the body of the world herself. This stone grows and acts almost like the bark on a tree, and it is just as light. Thus, we have a strong, semi-organic rock that can give, float, and heal. Even after it separates from Olua, buoyed to the trepizone, cloudstone has the ability to grow.
Cloudstone is abundant on the Fractal Oceans, but skitters were unable to do very much with it for several generations. Once they finally figured out how to transport and shape it so that it retained it shape and integrity, the skitters were unleashed. With this miracle substance, they built light, sturdy bridges that could span miles with very little maintenance. And so the archipelagan conquest began.
Other articles detail the stories of that conquest. This one is more about the biology and physical properties of cloudstone.
Cloudstone originates as a group of Olua's "cells," more crystalline in makeup and behavior, but serving much the same function as cells. As with any complex organism, the rock turtle has myriad cell types, each serving a different organ. However, most of these will never be touched by Olua's passengers. Practically the only cells that make it to the surface are her "scales," light and flaky after draining of fluid. They aren't dead, per se, as crystobiological functions can resume, but we can think of them as such when they reach organic beings.
With magic, or sufficient scientific command, a being can shape and strengthen cloudstone through crystal growth. They can encourage cellular function to resume, nudge growth in unviable but mechanically advantageous directions, or fuse multiple cloudstones together. When a specimen is "alive," it grows long-timescale-stretchy, so that you can tweak the shape of already-existing cells. (In a combat context, full-cover cloudstone armor can give the benefit of plate mail and Stoneskin, without the heavy drag.) It is an incredibly strong and versatile material, though not easily accessed. To those who have that power, cloudstone gives them a serious upgrade.
Naturally, colony skitters use this for evil.