Mwakitau — Kenyan Tsavorite Locality
Mwakitau — Kenyan Tsavorite Locality
A Taita Hills source in the broader Tsavo region producing vanadium-chromium green grossular
Mwakitau is a tsavorite-garnet locality in the Taita Hills of southeastern Kenya, near the Tanzanian border, within the broader Tsavo gem region where tsavorite was first discovered. The deposit produces vanadium- and chromium-coloured green grossular garnet — typically in sizes under two carats — and contributes to the Kenyan and international tsavorite supply through small-scale artisanal mining.
Geology
The Tsavo tsavorite deposits formed within Neoproterozoic metamorphic rocks of the Mozambique Belt, where graphite-bearing gneiss interlayered with calc-silicate rocks produced the unusual chemistry needed for vanadium-rich grossular. Tsavorite occurs in 'pinch-and-swell' nodules and lenses within these host units, recovered by following the productive horizons through hand pits and small open workings. The deposits are notoriously difficult to follow — productive zones often pinch out within metres — which is why most operations remain small-scale.
Quality
Mwakitau material shows the vivid green hue characteristic of tsavorite, coloured by vanadium with minor chromium. Stones are typically small; rough above five carats faceted weight is rare, and the population is dominated by sub-two-carat finished gems. Inclusions are common — tsavorite is a heavily included species across most sources — and eye-clean material at good size commands a sharp premium. Heat treatment is not used; tsavorite is one of the few important coloured stones that is essentially never enhanced.
Trade significance
Tsavorite from Mwakitau enters the supply chain through Voi, Mombasa, and Nairobi dealers, then onward to Bangkok, Jaipur, and Western markets. The locality does not command a specific origin premium — tsavorite is generally priced on colour, clarity, and size rather than on precise mine of origin within the Tsavo region. The broader Kenyan-Tanzanian tsavorite trade is itself relatively young, dating from Campbell Bridges' identification of the species in 1967, and remains an important East African coloured-stone export.