What is Nyerereite?
Nyerereite is a rare sodium-calcium carbonate from the active alkaline volcano Oldoinyo Lengai, one of the clearest mineral records of natrocarbonatite lava.
Mineralogy and crystal structure
Reference formula: Na2Ca(CO3)2. Nyerereite is an orthorhombic carbonate whose high-temperature and low-temperature forms reflect cooling history. Its sodium-rich chemistry and volcanic setting are more distinctive than crystal colour. Nyerereite is classified with carbonates and has a orthorhombic crystal system. Typical hardness is 3–3.5 on the Mohs scale and specific gravity is approximately 2.5–2.6.
Colour, lustre and habit
Typical colours include colourless, white, grey, cream. The usual tabular, granular, massive habit and vitreous, pearly lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Nyerereite forms in or is associated with high-temperature natrocarbonatite lava, volcanic fumaroles and alkaline carbonate flows. Important documented localities include Oldoinyo Lengai, Tanzania, with related alkaline volcanic occurrences under study.
A carbonate born in an active volcano
Nyerereite is a direct link to one of Earth's rarest lava types. Its crystals record natrocarbonatite, a fluid and chemically extreme volcanic melt unlike ordinary silicate lava.
Collecting and care
Protect from humidity and acids; retain the volcanic locality because alteration can rapidly change the surface.
