Nyerereite

Nyerereite is a very rare sodium calcium carbonate mineral with formula Na₂Ca(CO₃)₂. It forms colorless, platey pseudohexagonal orthorhombic crystals that are typically twinned. It has a specific gravity of 2.54 and indices of refraction of nα=1.511, nβ=1.533 and nγ=1.535. Nyerereite is not stable in contact with the atmosphere and rapidly breaks down. Collection specimens must be kept in a sealed argon environment.

It was first recognized and described from the Ol Doinyo Lengai carbonatite lavas in 1963 and named in honor of the president of Tanzania, Julius K. Nyerere (1922-1999). In the carbonatite lava it is associated with the potassium bearing gregoryite. It has also been reported from the Afrikanda alkaline intrusive complex, in the Kola Peninsula, Russia and from the Schoeller mine, Kladno, Czech Republic.

References

*Mindat
*Webmineral data
*Anatoly N Zaitsev and Anton R Chakhmouradian, Calcite â€" amphibole â€" clinopyroxene rock from the Afrikanda Complex, Kola Peninsula, Russia: mineralogy and a possible link to carbonatites. II. Oxysalt minerals, The Canadian Mineralogist 40 pp 103-120 (Abstract)
*Nyerereite, Czech Republic (Image)