This Wizard subclass was inspired by crystals and got way more complicated than originally intended.
Magical rocks said to channel the energies of the universe for healing and benificial properties. Some people believe. Some thing its junk. You learned how to harness this power and use it. Wizards of the crystal school have leraned what crystals are usful and the magical properties they contain. They use these powers to help allies and keep them in the fight.
Mechanically you can use a crystal or crystals for your spellbook and can switch some spells on a short rest. You can also create magical crystals with various magical abilities and hand them out to your party to buff them. At later levels your crystals have an aura of power, they become more powerful and you can change their effects more frequently.
- from the publisher's blurb