Used as a navigation tool by early explorers. It is a handheld device used to measure angles between celestial bodies and the horizon. Doing so can help the explorer plot their courses with near pinpoint accuracy.

This particular sextant appears to be other-worldly.

Using Ulrir's spltting maul, you are able to break in to a sealed iron chest. Instead of gold or other treasures, the chest contains maps. They appear to be maps from other planes, which immediately interest Nayo. She hands you the sextant, which was clearly used to create the various maps.