We present the research and development of fire-resistant sandwich structures using a mica-based inorganic paper core. The Miura-ori geometry of the core provides good strength and lightweight performance while allowing the relatively brittle fire-resistant mica paper to deform non-destructively. Combined with a geopolymer foam binder, the structure can withstand temperatures up to and beyond 1000  \(^\circ \) C for extended periods at a fraction of the weight of current protective systems.