glauc·o·phane 
(gloukə-fān′)
(gloukə-fān′)n.
A bluish-gray or bluish-black monoclinic mineral of the amphibole group.
[German Glaukophan : Greek glaukos, bluish gray + Greek -phanēs, appearing (from phainesthai, phan-, to come to light, appear; see bhā-1 in the Appendix of Indo-European roots).]