To activate it you must put a pygmy on the altar and then wait until it has finished taking out its heart then it will turn on and a hot beam of light will show and burn any pygmy that touches it. Note: If you put a avatar there it will take it's heart out then back in and your avatar will ride off on what seems to be a sun hoverboard.
The Sun Stone has five "phases". The Stone gains power each phase. You must sacrifice a Pygmy on the Stone's altar to move to the next phase.
1. Inactive does nothing.
2. The Stone is activated and you can burn Pygmies with it by using the Sun.
3. You can now move the Stone off of the altar, and crush Pygmies with it.
4. The Stone now has blades that can cut a Pygmy in half when dropped on one.
5. The stone can now eclipse the Sun or Moon. All you need to do is move the Stone in front of the Sun/Moon. Your Pygmies seem fine, but when you reveal the Sun/Moon you see that all that remains of your Pygmies is their eyes.
6.Not a phase but still sacrifices Pygmies. After you put your avatar on the altar, the avatar's heart goes back to the owner and then rides a sun hoverboard with blades that can chop the Pygmies' head off. Now that we have wasted your time on some of these we hope you enjoyed it.
There is a glitch which can revive the pygmy after the eclipse. You put the Sun stone in front of the Sun and then you keep it until the pygmy's eyeballs are visible. After that, grab quickly an eye before it disappears. The Pygmy is alive again!