Formula: Al₆B₅O₁₅(F,OH)₃
Mineral Class: borates
Crystal System: hexagonal
Gemmy Jeremejevite from Namibia occurs in well-formed, sharply crystallized, prismatic obelisk prisms with lustrous surfaces, sometimes two toned with a blue base and white terminations.
Mohs Scale: 6.5 - 7.5
Density (g/cm³): 3.28 - 3.31
Cleavage: ?
Colors: clear, white, yellowish, blue
Luster: vitreous
Fluorescence: -
Pleochroism: Colored stones: colorless - light blue-violet
Largest Jeremejevite crystal: ~5 cm, alledgedly up to 8-10 cm.
Largest faceted Jeremejevite: >4 ct
Deposits:
Ameib Farm / Usakos and Omaruru Distr./ Erongo Mountains / Namibia
Mile 72 Road Marker, Arandis / Swakopmund Distr. / Erongo Mountains / Namibia
Soktuj Gora / Adun-Cholon Range / Nerchinsk / Buryatia Republic / Russia
Eifel Mountains / Germany
Kukurt / Pamir Mountains / Tajikistan
Discovery: 1883
1st Description: 1883
History (excerpts from The Mineralogical Record ):
• Jeremejevite "was originally described by Damour (1883), the type specimens consisting of a few colorless, prismatic crystals to several centimeters from a pegmatite situated on Mt. Soktuy (a northern extension of the Adun-Chilon Range), Chitinskaya Oblast, in the Nerchinsk district of Transbaikal, Russia."
• "A second occurrence of jeremejevite, this time as deep blue crystals found near Mile 72, on the Cape Cross Sheet ... north of Swakopmund, Namibia in 1973 ... The initial discovery was made by a woman ... his wife frequently spent her days walking behind her husband's grader collecting pretty rocks. In 1973 the road leading to the Mile 72 fishing camp road was angled at approximately 45 degrees southward to the coast road from its current location. Consequently Mr. Marais' grader turned over a few jeremejevite crystals that had weathered out into the sand, and Tannie Klippie was there to pick them up. These specimens eventually made their way to the sharp eye of Usakos/Windhoek gem and mineral dealer Sid Pieters. At first glance Pieters thought them to be aquamarine, but an analysis identified them as jeremejevite. This was confirmed by a gemological analysis, performed by the Gemological Institute of America (Liddicoat, 1973), of a cut gem supplied by one of the authors (ERS)."
• "Since the Mile 72 discovery, occurrences have been found in Germany in the Eifel district (in prismatic blue crystals rarely exceeding 1 mm, and in yellowish crystals in tiny spherical aggregates) at Wannenköpfe near Ochtendung and Emmelberg (Hochleitner and Weiss, 2000), and also in the eastern and southwestern Pamirs, Tajikistan (Zolotarev et al., 2000)."
• "A new locality for blue jeremejevite was discovered in the Erongo Mountains in 2001, and has produced some fine, lustrous crystals."
Source: The Mineralogical Record / Jul/Aug 2002 by Wilson, Wendell E, Johnston, Christopher L, Swoboda, Edward R

Jeremejevite Mineral

Origin: Erongo Mts. / Usakos and Omaruru Distr. / Namibia

Photo by kind permission of © www.irocks.com, Dr. Robert Lavinsky.

Jeremejevite

Weight: 5.82 ct

Origin: Mogok / Myanmar

Photo by kind permission of © www.americanthai.com, Scott Davies.

Jeremejevite Mineral / Micromount

Origin: Emmelberg Mt. / Üdersdorf / Eifel Mts. / Rhineland-Palatinate / Germany

Photo by kind permission of © Stephan Wolfsried.

Jeremejevite Mineral / Micromount

Origin: Emmelberg Mt. / Üdersdorf / Eifel Mts. / Rhineland-Palatinate / Germany

Photo by kind permission of © Stephan Wolfsried. Willi Schüller Collection.

Jeremejevite Mineral

Origin: Namibia

Photo by kind permission of © www.trinityminerals.com, John Veevaert.

Jeremejevite

Weight: 0.19 ct

Origin: Namibia

Photo by kind permission of © www.djraregems.com, John & Donna Rhoads.

Jeremejevite

Weight: 1.31 ct

Origin: Mile 72 / Cape Cross / Swakopmund Distr. / Erongo Region / Namibia

Photo by kind permission of © www.irocks.com, Dr. Robert Lavinsky.

Jeremejevite Mineral Micromount

Origin: Emmelberg Mt. / Üdersdorf / Eifel Mts. / Rhineland-Palatinate / Germany

Photo by kind permission of © Stephan Wolfsried. Willi Schüller Collection.

Jeremejevite Mineral

Size: 3.2 x 0.8 x 0.68 cm

Origin: Mile 72 / Cape Cross / Swakopmund Distr. / Erongo Region / Namibia

Photo by kind permission of © www.mineralman.com, Jasun McAvoy.