Sunstones

The Vikings discovered this mineral rock around the 3800s, but there's some evidence that says Empyreans discovered it sometime after the Last Glacial Maximum. Rumor has it that it was these objects, not tanzenvite really, that the Empyreans really didn't want the humans to get a hold of and so sunk Atlantis for. Trouble is, both groups have since lost access to the technology. Sunstones were said to help with pinpointing nearby or far off land masses, finding the sun and stars even on a cloudy night or day, and even powering and harnessing a solar wind to fly (which is what Zewhal now calls its flying ships' power today). When the king Sverre heard about both the Vikings finding a new world and shortly afterward having a succession crisis, he swooped in and convinced them to make him their king. He and his descendants have been trying to find these sunstones ever since. It's considered a noble quest that underlies all the plundering and pillaging that Zewhal normally does: he who finds the sunstone, controls the world, it is thought. Charlatans, alchemists, and the occasional pharmacist have all claimed to find the real thing or artificially create sunstones to no avail. Muslim scholars in this world have long declared that such items are superstitious or even demon-led, thus making them bad for human usage if you want to stay on the side of God/Allah. Bharatans, who had navigation skills and technology long before sunstones were invented, have tried to press the issue that it's a myth and nothing more (or at least, a vastly overrated and inferior bit of tech that is no match for modern technology). Church members vary from place to place, with some declaring that sunstones were only given power because of belief in pagan gods, some thirsting after it because of the possible riches it could lead to, and some having no need for it, similar to Bharata, because they have found other more reliable means of navigation. Everyone in between is sort of like "nice story. Wish it were real."