bertrandite

[bur-truh n-dahyt]
noun
  1. a mineral, hydrous beryllium silicate, Be4Si2O7(OH)2, colorless or pale yellow, with a vitreous luster, occurring as tabular or prismatic crystals in pegmatites and hydrothermal veins.

Origin of bertrandite

1885–90; < French, after E. Bertrand, French mineralogist, who first described it; see -ite1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018