While your typical Crystali design can be pretty diverse, they can also come with some extra fancy traits. These are all loose descriptions and can be interpreted in many ways. A crystali may have many fun traits, but (I think) anything more than 1 or 2 of these would make a Crystali stand out like a sore thumb.

Polar - Extra fluffy or extra long tufts of fur. Most common in areas where it is colder.

Orphan Sources - Extra crystals that are not part of the 3 base clusters.

Vertebrate Tail - Having a tail. This gene is very undesirable since it seems to remove a lot of a Crystali's ability to use magic. Possibly due to the flow of magic through their bodies being interrupted by having a nonexistent or highly unusual tail cluster.

Anomaly - Having hoofs instead of paws, or having some scales on certain parts of the body. This trait encompasses pretty much any mutation that changes their base physiology.

Floating Sources - floating crystals

Chroma - Having 2 drastically opposing elements, or an element so complex that their magic mist appears to be significantly multicolored.

Wings - Winged crystali are incredibly rare. This gene has largely stayed within families with royal blood. The wings are usually just an excess of magic venting through an extra cluster.