Crystal Dart
The Crystal Dart is a canonical MuTe level 10 spell introduced in ArM5, p. 154.
R: Voice, D: Mom, T: Ind Req: Rego
Opinions and Commentary
As a low-level spell that produces significant damage, this is one of the more popular damaging spells and can be found in many wizard's grimoire. The presence of a requisite, however, and the somewhat-unpopular Art of Muto, means that achieving high penetration with this spell may be somewhat difficult.
Note that the spell affects a piece of earth at your feet, Mutoing it into the crystal, and only then sending it towards the target. This isn't crystal-clear from the spell's description, but this is how it works.