Materia from Final Fantasy VII is crystalized "Mako" which is the liquid essence of the Lifestream and thus with Materia you can summon the power and wisdom of the Lifestream to manipulate nature itself, thus "magic". Like Chaos Drives it also comes ina variety of colours for various uses, such as Summon♦, Magic♦, Command♦, Support♦ and Independant♦.
Chaos Drives, what I pressume, is Chaos Energy in a crystalize state, though is is unconfirmed if this crystal is of mineral beryl as the Chaos Emeralds are (emeralds being a beryl). Chaos Drives were primarily used in raising chao as unlike Chaos Emerald where despite different colours each emerald is of equal power and use, Chaos Drives contribute to distinct abilities such as making your chao faster♦, stronger♦, better at flight♦ or swimming♦. Later on Chaos Drives were used to charge Sonic, Shadow and Silver's abilities.
Forcejewels I know little of. I been meaning to start an article on them. What I do know about them is that they are rainbow-coloured jewel from Sonic Shuffle. They have mysterious powers and effects as they are collectable crystals from Maginaryworld. Some of them will give you positive effects, where you can move fast by using a few cards at the same time, while some will actually give you negative effects, like destroying your Forcejewels that you had at the time. For an RPG I can imagine a variety of Forcejewels making it to Sonic's world which his friends can use to improove there abilities such as burst of elemental magic. I aleady have ideas for the summoning system.
Anyway, Im just wondering what kind of these crystals would be best for when it comes to learning magic and abilities in Sonic's world, despite the fact Sonic games are not RPGs. While I like ForceJewels, they ar enot native to Sonic's world while Chaos Drives could perhaps function more as power source but with programmed code for magical or ability use. I plan the use of Chaos Drives in Sonic World MMOG as chao raising itself is an important gameplay concept. However for a general Sonic RPG I favour more for the ForceJewels.
What are your oppinions on the matter on the nature of these crystals and itr's effects in Sonic's world? As well as my ideas for them.