Home >  Term: beryllonite
beryllonite

Beryllonite is a rare sodium beryllium phosphate mineral with formula NaBePO4. The tabular to prismatic monoclinic crystals vary from colorless to white or pale yellowish, and are transparent with a vitreous lustre. Twinning is common and occurs in several forms. It exhibits perfect cleavage in one direction. The hardness is 5.5 to 6 and the specific gravity is 2.8. Refractive indices are nα = 1.552, nβ = 1.558 and nγ = 1.561. A few crystals have been cut and faceted, but, as the refractive index is no higher than that of quartz, they do not make very brilliant gemstones.

0 0
  • ส่วนหนึ่งของคำพูด: noun
  • อุตสาหกรรม/ขอบเขต: Geology; Mining
  • Category: Minerals
  • Organization: Wikipedia

ผู้สร้าง

  • John Wiley
  • (United States)

  •  (Silver) 584 points
  • 0% positive feedback
© 2024 CSOFT International, Ltd.