stelliet
Stelliet is a term that has appeared in speculative fiction and some non-scientific geology discussions as the name of a hypothetical mineral or alloy associated with stars. There is no generally accepted, peer-reviewed definition of stelliet in real-world mineralogy, and it is not listed by the International Mineralogical Association. In most usages, stelliet is described as a rare, crystalline substance with properties linked to stellar energy, such as luminescence, heat resistance, or unique fracture patterns, though these descriptions vary by author. Because stelliet is not an established mineral, its chemical composition and crystal structure are not standardized.
In fictional contexts, stelliet is often portrayed as formed under extreme conditions, such as in stellar nebulae
Etymology: the name combines the word stellar with a suffix common to mineral names, emphasizing a connection