A Windstone is a powerful crystal and an important item necessary for travel around the Spiral. Coming in a variety of colors, the Windstones are absolutely necessary to journey through the Stormgates that exist in the Skyways.
Windstones were first discovered by the people of Valencia, who used them to help ships through the otherwise impassable Stormgates that existed throughout the Spiral. Scholars noted that certain Windstones could only help ships go through cerain gates; for instance, a Violet Windstone would allow any ship to enter Monquista from Skull Island (which is not a very large distance) and vice versa, whereas a Yellow Windstone could allow any sailor to go from as far as Marleybone all the way to Aquila and back. An Orange Windstone which will be released eventually, will be required to continue the Pirate101 storyline after Valencia 2, thus allowing pirates to travel to the spooky realm of Darkmoor and the frozen tundra realm of Polaris
As time went on, the various nations of the world realized that it would prove beneficial that a ship be capable of using multiple Windstones. Thus, a special device was made that housed every Windstone ever discovered by the Spiral's nations. Naturally, these objects were sought after by more than just the nations of the Spiral- pirates also hungered for them and have been known to go crazy whenever there is promise of a Windstone (though, if a derelict ship has been found by pirates and it has a Windstone, then the pirates will gladly "relieve" the ship of its contents).
The player is first introduced to Windstones by the Majordomo of Puerto Mico. He tells the player that Windstones can allow ships to journey through Stormgates to other worlds. Unfortunately, the player lacks a Violet Windstone, which is necessary for travel to Monquista. Luckily, the Majordomo has a solution- privateers from Marleybone plague the local skies, giving the player a chance to rob a Marleybone ship for a Windstone.