Mineralpedia Details for Leucophanite

Named for the Greek for leuco, meaning “white,” and phaintaid, meaning “to appear,” in reference to its common white appearance. It is a rare, but widespread mineral and can be found in Norway, Russia, Greenland, Canada, and a couple others. It occurs in pegmatites in augite syenite at its Norwegian locality, and in albitization zones in pegmatite at the contact of alkalic massifs and quartz-sericite schists in the Baikal massif in Russia. Leucophanite will fluoresce pink to a violet-blue in long-wave and short-wave ultraviolet light and is strongly phosphorescent. It is also pyroelectric and generated a charge in response to heat.

Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/leucophanite.pdf

Formula

NaCaBeSi₂O₆F 

Crystal System

Triclinic 

Crystal Habit

Tabular 

Cleavage

Good, Good, Distinct 

Luster

Vitreous (Glassy) 

Color

white, greenish yellow, yellow, light green 

Streak

white 

Class

Triclinic - Pedial 

Fracture

Brittle 

Hardness

4 

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Lemon yellow, pseudocubic crystals to 3mm with Aegerine.

Well formed light lemon yellow, dull tabular crystals to 2.5mm with square cross sections and pyramidal/pinacoidal terminations associated with pink Serandite.

Faint yellow blocky crystals of Leucophanite to 1.5cm in coarse crystalline pegmatite matrix of mostly Plagioclase. Leucophanite was discovered in 1840 on the Island of Låven located in the Langesundsfjorden district. Since then being discovered several pegmatites in Norway (Telemark and Vestfold counties), Greenland (Ilímaussaq complex and Narsaq), Russia (Khibiny Massif of the Kola Peninsula), and Canada (MSH). It is another rare beryllium silicate found in nepheline syenites.

NOTE: The Island of Låven was declared a nature preserve in 1970 because of its unique mineralogy and collecting is prohibited by law.