Early 19th century; earliest use found in John Pinkerton (1758–1826), historian and poet. From Miage, the name of a glacier near Mont Blanc where the rock was first discovered by H. B. de Saussure + -ite.
Definition of miagite in US English:
miagite
nounˈmʌɪədʒʌɪt
Geology rare
An orbicular gabbro.
Origin
Early 19th century; earliest use found in John Pinkerton (1758–1826), historian and poet. From Miage, the name of a glacier near Mont Blanc where the rock was first discovered by H. B. de Saussure + -ite.