New (fictional) materials to control gravity.
There of course aren't any real materials which control gravity, but materials with heavy influence upon it are common in science fiction (Mostly rocks).

Off of the top of my head, a quite notorious Ore is Fortnite's Kinetic Ore (Creates hop rocks, shockwave items), it & its derivatives lessen the force of gravity when agitated.
There's also Cavorite, from H.G. Wells' The First Men in the Moon, immune to gravity

I haven't yet found any materials which increase the gravity of others, likely because it's less fun, and I wouldn't like to simply invent one, since that's not the nature of fictional materials in this game.

Anyways, a few suggested element properties
KNOR - Kinetic Ore
- Reduces local gravitational effects in ebbing waves, the rate of these ebbs increase with temperature
KNTC - Refined Kinetic Ore, Kinetic Stone
- Reduces effects of all local gravities in a radius increased by temperature.
CVRT
- Inverts the effect of local gravities, increasing radius & severity with temperature