Jeremejevite

JEREMEJEVITE Locality: Wannenköpfe, Ochtendung, Eifel region, Germany image width: 1,5mm © Fred Kruijen.

Chemical Formula: Al6(BO3)5(F,OH)3
Locality: Soktujberg, Adun-Tchilon and Baikal, Russia.
Name Origin: Named after the Russian mineralogist, P. V. Jeremejev (1820-1899).
Jeremejevite is a rare aluminium borate mineral with variable fluoride and hydroxide ions. Its chemical formula is Al6(BO3)5(F,OH)3.

It was first described in 1883 for an occurrence on Mt. Soktui, Nerschinsk district, Adun-Chilon Mountains, Siberia. It was named after Russian mineralogist Pavel Vladimirovich Eremeev (Jeremejev, German) (1830–1899).

It occurs as a late hydrothermal phase in granitic pegmatites in association with albite, tourmaline, quartz and rarely gypsum. It has also been reported from the Pamir Mountains of Tajikistan, Namibia and the Eifel district, Germany.

Physical Properties

Cleavage: None
Color: Colorless, White, Yellowish white, Bluish white.
Density: 3.28 – 3.31, Average = 3.29
Diaphaneity: Transparent
Fracture: Conchoidal – Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Hardness: 7 – Quartz
Luminescence: Non-fluorescent.
Luster: Vitreous (Glassy)
Streak: white

Photos :

Jeremejevite Erongo Mountains, Namibia Miniature, 4.7 x 0.9 x 0.6 cm © irocks
Jeremejevite Erongo Mountains, Namibia Miniature, 3.6 x 1.6 x 1.0 cm © irocks
Jeremejevite Erongo Mountains, Namibia Miniature, 4.6 x 0.7 x 0.6 cm © irocks
Emmelberg, Üdersdorf, Daun, Eifel, Rhineland-Palatinate, Germany © Fred Kruijen