loadstone

n.

磁铁矿，磁性氧化物；

loadstone
On the Loadstone and magnetic sodies
STITCHED SHIPS AND LOADSTONE ROCKS
[From loadstone to magnetic resonance tomography. Historical remarks on magnetism]
Permanent magnet material from loadstone to rare earth cobalt
Permanent magnet material from loadstone to rare earth cobalt
The Source of Ahab's Lordship Over the Level Loadstone
Book-Reviews: William Gilbert of Colchester, On the Loadstone and Magnetic Bodies
The Science of Magnetism Before Gilbert Leonardo Garzoni's Treatise on the Loadstone
Benedetto Castelli's Discourse on the loadstone (16391640): the origin of the notion of elementary magnets similarly aligned