Which of the following natural minerals has the strongest magnetic field on the earth today? A diamond b jiuyanshi shale (dzi bead) c crystal

In material science and mineralogy, the magnetism of crystals is determined by their magnetic domains. Diamonds and dzi beads cannot have magnetic domains because of their crystal structure. Crystals have piezoelectric properties and electric domains, but they are not magnetic. . . That's what science says. From the perspective of geomantic omen, geomantic omen comes from ancient cultural legends. At that time, there was no such thing as diamonds, so there was no need to consider them. The dzi beads are a kind of ornaments to ward off evil spirits in Tibetan Buddhism. In mineralogy, they are only recognized as polycrystalline agates, which are valuable in geomantic omen. But now there are many fakes, and the so-called magic beads are also fake. I hope to study hard before I start. Crystal is really piezoelectric, and other properties are legendary. Jewelry is a psychological comfort, as long as you like it. What hardness upstairs has nothing to do with magnetism, it's all bullshit.