Spessartine high spessartine content tend toward a light orange hue, while almandine prevalence induces red or brownish hues. Spessartine Spessartine, sometimes mistakenly referred to as spessartite, is a nesosilicate, manganese aluminium garnet species, MnAl(SiO). The mineral spessartine should not be confused with a type of igneous rock (a lamprophyre) called spessartite. Spessartine's name is a derivative of Spessart in Bavaria, Germany, the type locality of the mineral. It occurs most often in granite pegmatite and allied rock types and in certain low-grade metamorphic phyllites. Sources include Australia, Myanmar, India, Afghanistan, Israel, Madagascar, Namibia, Nigeria, Mozambique, Tanzania and the United States. Spessartine
Gemstone irradiation the country. All neutron- or electron beam-irradiated gemstones must be tested by an NRC-licensee prior to release for sales. In India, the Bhabha Atomic Research Centre started irradiating gemstones in the early 1970s. In Thailand, the Office of Atoms for Peace (OAP) conducts the process for private sectors, irradiating of gemstones from 1993 to 2003. The most commonly irradiated gemstone is topaz, which becomes blue after the process. Blue topaz is very rare in nature and almost always the result of artificial irradiation. According to the American Gem Trade Association, approximately 30 million carats () of topaz are irradiated every