N'gori

A crystal of magical origin, many say it is pure magic condensed into a crystalline form.
They can be of many different colours and are most often perfect in their form, be it a sphere, a cube, a cardioide or a crystal in snowflake form or a spike...

They are used by various magical traditions for various purposes, quite often as a source for additional magical energy and by at least one the are the sole power source for any spellcasting or ritual.