Crys

Crys pronounced like "Chris" is a source of power. In Gothic San Angeles people are strongly against technology and use magic instead. Crys is the main source of power for many things. There are different housing to store it and the housings can be recharged. Both the housings and crys charges are expensive and could be a source of trade, but depending on the political scene it make require restricted for legal ownership.

Uses
Ammunitions for guns - the guns can be upgraded to give elemental damage and/or longer range

Fuel for Flying Cars

Magic Goggle charges - allow wearer to see if an object has a magical aspect and with the aid of analyze magic skills, tell the nature of object

Explosive if you mess around with it on purpose or otherwise