A Magic Purple Gem

On the other side of town, a teenage boy named Billy was playing football with his friends at a park near his house. His day was going as normal as any other day at the park ... until he found it. After catching a long pass of the football, he discovered a small purple gem lying near the bottom of a gnarled old tree. He reached over and grabbed hold of it and that's when it began to glow ... but only for a moment and Billy didn't notice it. Standing up with the football in one hand and the purple gem in the other, he walked back towards his friends, not even realizing that the purple gem was actually magic! But what did this magic purple gem do?