What does ferromagnetic mean in mineralogy ?

Ferromagnetic : definition

This term designates minerals having a very high specific magnetic susceptibility, greater than 1500 x 10-6 CGSEM, which gives them the property of being attracted by a usual hand magnet and of deflecting the needle of a compass.

These ferromagnetic minerals are very few in number, the most common being iron, maghemite (over 100,000 ksi units), magnetite (20,000 to 80,000 ksi) and pyrrhotite (1,500 to 6,100 ksi).