dumortierite
noun
du·mor·ti·er·ite du̇-ˈmȯr-tē-ə-ˌrīt 
also dyu̇-
: a bright especially blue mineral consisting of a borosilicate of aluminum
Word History
Etymology
French dumortiérite, from Eugène Dumortier †1876 French paleontologist
First Known Use
1881, in the meaning defined above