bertrandite

noun

ber·​trand·​ite

ˈbər-trən-ˌdīt

plural -s

: a mineral Be₄Si₂O₇(OH)₂ consisting of a beryllium silicate occurring in hard colorless or pale-yellow prismatic crystals (hardness 6–7, specific gravity 2.59–2.60)

Word History

Etymology

French, from E. Bertrand, 19th century Frenchman who first described it + French -ite

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

1. Expanded definitions
2. Detailed etymologies
3. Advanced search tools
4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now