I'm more on the same page as Jackal, though i still don't see Rock, Water or Wind as being particularly distinct, nor characterful. Whereas the others are more spontaneous energy states, Water and Rock are physical things, and Wind just isn't that... well... Damage-y... I mean, look at Air Benders, that's more characteristic of Wind... Yeah, it CAN be pretty damaging under the right circumstances, but you're generally looking at extremely broad AOE effects, not the typical attacks of a Destruction Mage.
The basic 3, Fire, Frost and Lighting, are all easily manageable as spontaneous energy states in an environment. Heat, Cold and Static are far easier to achieve using magical energy than creating matter. And even then, that manipulation of matter is more the domain of Alteration than it is Destruction.
Entropy, on the other hand, is something that's been implied in a lot of the lore, but never really handled. It is the cancellation of energy, the annihilation of matter and the anti-creation. In many ways, it's anti-magic, the purest form of destruction, the endless obliteration that is Sithis. It's also clutter removal and should destroy everything but specially protected artefacts...
The characteristics i've tinkered with are basically...
Fire; Damages Health, causes burning. Burning targets take damage over time and damage those nearby, and can set off flammables in the environment.
Frost; Damages Health and Stamina, causes freezing. Freezing is a stacking de-buff that slows movement and action speed.
Lightning; Damages health and Majicka, has a chance to Arc. Arc does half damage to nearby targets
Entropy; Damages Health. Disintegrates everything.
I think things like Velocity, Impact Force and Cost are better handled by Qualities and Delivery, and things like location damage and how it interacts with defences is more a characteristic of armour type, quality and materials, or the specific defensive spell you are using.