Twig, witnessing a massive bolt of stormphrax bury itself in absolute darkness.

Stormphrax was a type of crystal made from pure lightning, created in Great Storms over the Twilight Woods. While in an illuminated area, Stormphrax was extremely volatile, and an attempt to grind the crystals would unleash the power of lightning in the form of a mighty explosion. In absolute darkness, Stormphrax lost its volatility, but took on a truly enormous weight. A thimbleful of stormphrax in absolute darkness was said to weigh more than a thousand Ironwood Pines. In the glow of twilight, Stormphrax could be safely ground into the water-purifying substance known as phraxdust.

Role in the First Age of Flight

In the First Age of Flight, the Sanctaphrax rock was weighted down by a chest of Stormphrax placed in the absolute darkness of the Treasury Chamber. Without it, the buoyancy of the Sanctaphrax rock would be too great, causing it to break free of its moorings and drift away into Open Sky. The goal of Knights Academic was to retrieve Stormphrax during a Stormchasing voyage. Stormphrax was considered to be so sacred by the academics of Sanctaphrax that it was considered blasphemy for unworthy eyes to so much as gaze upon it. Those unauthorized individuals caught stealing or even looking at stormphrax faced the death penalty.

The illicit stormphrax experiments of Vilnix Pompolnius led to the discovery of phraxdust, which gave rise to a black-market stormphrax trade in Undertown. The constant theft of stormphrax from the Treasury led to an escalating crisis in Sanctaphrax, the far-reaching consequences of which also jeopardized the water market of Undertown. In addition to this, Santaphrax threatened to break free of its moorings with the supply of stormphrax, utilized to weigh down the floating city, at such dangerously-low levels. It was impossible to attain more stormphrax, since Vilnix had banned stormchasing. Disaster was averted when the Professors of Light and Darkness made a deal with Cloud Wolf to obtain more stormphrax and Twig brought an enormous chest of stormphrax to the great floating city, some of which was also distributed equally among the Undertowners.

Role in the Third Age of Flight

During the Third Age of Flight, stormphrax was put to everyday use. Phraxmines in the Twilight Woods allowed for the retrieval of shards of stormphrax buried in ancient lightning strikes. These phraxcrystals were then used to power the mighty sky vessels known as Phraxships.

Stormphrax and phraxdust also found practical application in hundreds of everyday objects, from lamps to guns. Shards of phraxcrystals were powerful sources of energy, and individual crystals could power ships or weaponry for years without needing to be replaced. Because of its usefulness and power, stormphrax became an incredibly valuable commodity. The trade in phraxcrystals was the driving force behind the expansion of the mighty metropolis of Great Glade and its central role in the Edgeworld economy.