We have already created a free HoloStudy geology lesson! It covers the most common aspects of geology. It is available for download at the Microsoft Store for free!
According to Windows Report, HoloStudy demo app is rated among the Top 10 best applications since the Microsoft HoloLens headset became available. One of the HoloLens creators, Alex Kipman, was among the first users to test the HoloStudy app at the official release.