I've read that Florida avocados have a very high magnesium content; a lot higher than other types of avocados. (kimberlysnyder.com)
Cacao's high magnesium content is also helpful for lowering high blood pressure, sugar cravings, low libido (just saying!) (heathermcclees.com)
Because of their high magnesium content, cashews, almonds, and pumpkins seeds are the nuts to turn to if you suffer from migraines. (mindbodygreen.com)