JEREMEJEVITE: Nerchinsk, Siberia, USSR (0.5, 0.4)
Until the Namibian material was found, jeremejevite was an exceedingly rare mineral available only in microscopic grains. The African crystals are amazing in being both large and gemmy. Few gems have been cut from the material since the crystals are prized by collectors and the extent of the find is unknown. The crystals are not abundant at the locality, so jeremejevite will remain an extremely rare collector gemstone.
Jeremejevite Value
The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.
Jeremejevite Information
| Data | Value |
| Name | Jeremejevite |
| Crystallography | Hexagonal; crystals elongated and tapering; also small grains. |
| Colors | Colorless, pale blue-green, pale yellow-brown. |
| Luster | Vitreous. |
| Hardness | 6.5-7.5 |
| Density | 3.28-3.31 |
| Birefringence | 0.007-0.013. |
| Cleavage | None; fracture conchoidal. |
| Stone Sizes | No gems have been reported from the USSR material. However, the Swakopmund crystals have been cut, with gems up to about 5 carats possible. These are a lovely blue-green color, are relatively easy to cut, and are hard enough for wear. Typical faceted stone sizes are from under I carat up to about 2 carats. |
| Luminescence | None. |
| Spectral | Vague absorption band at about 5000. |
| Formula | Al6B5O15(OH,F)3. |
| Pleochroism | Light cornflower blue/colorless to light yellow (Namibian material). |
Optics: e= 1.637-1.644; o= 1.644-1.653. Uniaxial (-).
Cores of crystals sometimes biaxial (from USSR), 2V= 0-50°
Biaxial rims also sometimes observed in Namibian material.
Occurrence: Cape Cross, near Swakopmund, Namibia: very long pyramidal crystals (up to 2 cm), blue-green color: e = 1.639; o = 1.648; birefringence 0.007.
A few single crystals were found on Mt. Soktuj, Nerchinsk district. East Siberia, USSR, in loose granitic debris under the turf.
Comments: Until the Namibian material was found, jeremejevite was an exceedingly rare mineral available only in microscopic grains. The African crystals are amazing in being both large and gemmy. Few gems have been cut from the material since the crystals are prized by collectors and the extent of the find is unknown. The crystals are not abundant at the locality, so jeremejevite will remain an extremely rare collector gemstone.
Name: After Pavel V. Jeremejev, Russian mineralogist and engineer.
