scapolite
noun
scap·o·lite ˈska-pə-ˌlīt 
: any of a group of minerals that are essentially complex silicates of aluminum, calcium, and sodium and that include some used as semiprecious stones
Word History
Etymology
French, from Latin scapus shaft + French -o- + -lite; from the prismatic shape of its crystals
First Known Use
1802, in the meaning defined above