Ah, with the addition of the mention of throwing the stones, and that they had symbols inscribed on them, could it be Di-Gata Defenders, a 2006 Canadian animation?
The humans, or RaDosians, of this world came from another planet. The planet's inhabitants were mostly dark-skinned, white haired individuals with glowing blue eyes. However, these people were struck with a life-destroying Toten'Ka virus, which had spread across their planet and killed millions. A small team of RaDos Primes (the name of these original aliens) escaped from their planet on a starship. These original humans eventually crash landed in RaDos. The sun and atmosphere of RaDos began to take effect on their physical forms, turning them into the people of the current timeline. But in doing so, they eventually exiled the original inhabitants, the Mortigarians, a race of amphibious snake-like humanoids to live under the sea. The people that live in RaDos as of the current timeline are the descendants of these first RaDosians.
Before the humans arrived in this world, mystical beings called the Primordials roamed the realm. Their bodies used mystical energies as their life force. As they died, their life force leeched into the rocks of Di-Gata Mountains. Humans soon crash landed on the planet, caused by a stowaway creature named the Wrath-norak and a virus from their dying planet. Under Rados' sun, man's skin colour soon changed. Man was then able to mine the enchanted rocks found in the mountains, but were only able to recover energy from eight of the eleven sigils. Many rocks were mined by man, then carved into dice-like Di-Gata stones, and these were then carved with the sigil their power contained. From this point onward, anyone who used these stones were called stone casters or stone-slingers. It was believed that the first people who used these stones of power were called the Chi'Brek Tribe. This tribe was also the first tribe to document the arrival of the human race onto the planet.
There are currently ten known power forms in RaDos called Sigils. These sigils take up energy forms inside of Di-Gata Stones. But because the power of one sigil isn't as strong as the other, multiple sigils must be used, creating Henges. This creates a far greater concentration of power. However, some sigils do not need to be formed into henges, due to the extreme power that is contained within them (Vitus and Nostrum Vitae).
I previously provided this as an answer here.