Müller's glass
/ˌmʊləz ˈɡlɑːs/ /ˌmʊləz ˈɡlas/(also Muller's glass) Mineralogy
noun
= hyalite.
Origin
Late 18th century; earliest use found in Richard Kirwan (1733–1812), chemist and mineralogist. From the genitive of the German surname Müller, supposedly the name of its discoverer + glass.