Loadstone refers to naturally occurring pieces of intensely magnetic magnetite that were used for magnetizing compasses.
Iron, steel and ordinary magnetite are attracted to a magnetic field, including the Earth’s magnetic field. Only magnetite with a particular crystalline structure, lodestone, has the coercivity to act as a permanent magnet and attract and magnetize iron.
In China, the earliest literary reference to magnetism lies in a 4th century BCE book called Book of the Devil Valley Master “The lodestone makes iron come or it attracts it”. The earliest mention of the attraction of a needle appears in a work composed between 20 and 100 CE (Louen-heng): “A lodestone attracts a needle.” By the 12th century the Chinese were known to use the lodestone compass for navigation
Load-bearing stone masonry is mainly found in the historical centers of Greek cities and provinces where the main load-bearing structure consists of stone masonry walls. The walls are built using local field stones and lime mortar. The floors and roof are of timber construction. The seismic performance is generally poor.
Loadstone is also a precious stone that is believed to possess a variety of magical qualities.
When ill one holds it in the hands and shakes it well; it cures wounds, snakebites, weak eyes, headaches, and restores health.
A saying has it that the possessor of the loadstone may walk through reptiles in safety, even when the “black death” accompanies them. Orpheus said, “with this stone you can hear the voices of the gods and learn many wonderful things;” that it has the property of unfolding the future; and if held close to the eyes it will inspire the divine spirit. A loadstone is not a desirable gem to have on your person.