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.

It occurs as a secondary beryllium mineral in granitic and alkalic pegmatites. It was first described from complex crystals and as broken fragments in the disintegrated material of a granitic vein at Stoneham, Maine, where it is associated with feldspar, smoky quartz, beryl and columbite. It was discovered by James Dwight Dana in 1888, and named beryllonite for its beryllium content.

References

*Palache, C., H. Berman, and C. Frondel (1951) Dana’s system of mineralogy, (7th edition), v. II, pp. 677–679
* [http://www.mindat.org/min-644.html Mindat with location data]
* [http://www.webmineral.com/data/Beryllonite.shtml Webmineral data]
*1911


Wikimedia Foundation. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • beryllonite — /beuh ril euh nuyt /, n. a mineral, sodium beryllium phosphate, NaBePO4, occurring in colorless or light yellow crystals, sometimes used as a gemstone. [1885 90; < Gk berýll(i)on (béryll(os) BERYL + ion dim. suffix) + ITE1] * * * …   Universalium

  • beryllonite — noun A rare mineral, sodium beryllium phosphate, with the chemical formula NaBePO; found especially in Maine …   Wiktionary

  • beryllonite — be·ryl·lo·nite …   English syllables

  • beryllonite — bəˈriləˌnīt noun ( s) Etymology: New Latin beryllium + English on + ite : a mineral NaBePO4 consisting of sodium beryllium phosphate occurring in light colored topazlike orthorhombic crystals (hardness 5.5 6, specific gravity 2.85) …   Useful english dictionary

  • List of minerals A-B (complete) — It is currently not possible to have a complete list of minerals . The International Mineralogical Association is the international group that recognises new minerals and new mineral names, however minerals discovered before 1959 did not go… …   Wikipedia

  • List of minerals — This is a List of minerals for which there are Wikipedia articles. Mineral variety names and mineraloids are to be listed after the valid minerals for each letter.For a complete listing (about 4,000) of all mineral names: List of minerals… …   Wikipedia

  • Esperite — Infobox mineral name = Esperite category = Silicate mineral boxwidth = boxbgcolor = caption = Esperite under ultraviolet light formula = PbCa3Zn4(SiO4)4 color = White habit = Typically massive system = Monoclinic Prismatic (2/m) twinning =… …   Wikipedia

  • Indice (optique) — Indice de réfraction Image animée des fronts d onde émis par une source ponctuelle au dessus d un dioptre, mettant en évidence le phénomène de réfraction. La zone inférieure a un plus grand indice de réfraction et donc une vitesse de phase plus… …   Wikipédia en Français

  • Indice De Réfraction — Image animée des fronts d onde émis par une source ponctuelle au dessus d un dioptre, mettant en évidence le phénomène de réfraction. La zone inférieure a un plus grand indice de réfraction et donc une vitesse de phase plus faible que la zone… …   Wikipédia en Français

  • Indice de refraction — Indice de réfraction Image animée des fronts d onde émis par une source ponctuelle au dessus d un dioptre, mettant en évidence le phénomène de réfraction. La zone inférieure a un plus grand indice de réfraction et donc une vitesse de phase plus… …   Wikipédia en Français

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”