Umbalite

A gem trade name for a garnet intermediate between pyrope and spessartine, from Tanzania and Kenya.

Originally described from Umba River (Umba Valley), Tanga Region, Tanzania in 1978.

When umbalite was first discovered in the 1960s by miners extracting rhodolite garnets in the Umba River Valley of Tanzania, it was first thought to be a variety of spessartine garnet because its colour was markedly different to what was usually obtained and so it was initially discarded. Later, a few samples were analysed and the garnet was deemed to be a pyrope dominant pyralspite (pyrope/almandine/spessartine mix), although the almandine content was generally low. However, over the following years subsequent analysis and research has found that the majority of garnet material known as umbalite or malaia (malaya garnet) is actually a variable pyrope-spessartine mix and this garnet is now widely regarded as being a pyrope-spessartine variety.

The main localities (discovered in the mid-1960s and early 1970s) for these garnets are in East Africa (the Umba mining region bordering Tanzania and southern Kenya), with smaller deposits found in southern Tanzania in 1993. Similar material was found in Sri Lanka in the 1980s and discoveries were also made near Bekily, Madagascar in the late 1990s and in Manica, Mozambique in 2016 as well.