Quantcast

The Mineral jeremejevite

Elongated LargeJeremejevite Crystal

Jeremejevite is a rare borate mineral, best known for its aesthetic blue and gemmy crystals. It is one of the more difficult minerals to pronounce; the correct pronunciation is "Yeremiyaivite." Jeremejevite was first described in Siberia in 1883, and is named after Russian mineralogist Pavel Vladimirovich Jeremejev (1830–1899). The last name is Germanized from the Russian "Eremeev".

Chemical Formula

Al6B5O15F3

Color

Blue, light blue, purplish-blue, yellow, golden-brown. Sometimes color zoned, with a deeper blue zone and lighter blue color to nearly colorless zone.

Crystal System

Hexagonal

Properties

Streak
White
Hardness
7
Transparency
Transparent
Specific Gravity
3.2 - 3.3
Luster
Vitreous
Cleavage
None
Fracture
Conchoidal
Tenacity
Brittle

Crystal Habits

Crystals are in prismatic hexagonal shape, sometimes with terminations closely resembling Quartz. Crystals may be very tall and slender, though rarely larger than 5 cm. Deeply etched floater crystals are also known. Also in micro-crystal aggregates of prismatic crystals, radiating, and in micro ball-shaped aggregates.

Additional Information

Composition
Aluminum fluoro-borate
In Group
Borates; Anhydrous Borates
Striking Features
Crystal habits, hardness, and mode of occurrence
Environment
Granite pegmatites and xenoliths in volcanic scoria.
Rock Type
Igneous

Uses

Jeremejevite is a rare mineral, and good examples of this mineral are highly valued by collectors. It is occasionally cut as a rare and valuable collector's gemstone.

Noteworthy Localities

The best known examples of Jeremejevite are from the Erongo Region, Namibia, where beautiful, gemmy blue prismatic crystals up to 5 cm have been found. The two most important localities in Erongo are the Ameib Farm 60, Usakos, Karibib District; and the beach at Mile 72, Swakopmund District.

A relatively new find of Jeremejevite, in large prismatic yellow and golden brown crystals, is the Pantahole Mine, Loi-sau mountain, Mogok, Myanmar (Burma). The type locality of Jeremjevite, which produced crystals resembling Aquamarine, is Mount Soktuj, Adun-Chilon Mountains, Nerchinsk, Russia. Micro crystal with interesting habits come from the volcanic areas of the Eifel Mountains, Rhineland-Palatinate, Germany, with clustered crystal groups from the Emmelberg Quarry, Üdersdorf; and radiating micro blue crystals and balls from the Wannenköpfe Quarry, Ochtendung.

Common Mineral Associations

Quartz, Orthoclase, Plagioclase, Sanidine, Tourmaline

jeremejevite Photos



Close

Copyright © 2021. Minerals.net

View on Full Site