Float-stone
From Tardis Wiki, the free Doctor Who reference
Float-stones are made of Axite ore, found in the rocks on the planet Karagula which when fused together, this gravity repellent material allows the platform structures of the Karagulans to float about half a metre above the planets surface. Smaller pieces make accurate ‘ammo’ for hand-held slingshots having a truer aim.
Lorton was a particularly good shot with a float-stone sling.
