Mandarin Garnet (or Spessartine) is an orange to red-orange variety of Garnet and the name comes from the Spessart mountains in Bavaria, Germany where it was originally discovered. Other sources include Australia, Myanmar, India, Afghanistan, Israel, Madagascar, Tanzania and the United States. These gemstones have a remarkably high refraction of light, giving it an exceptional brilliance. Even in unfavorable lighting conditions, well cut Mandarin garnets will sparkle brilliantly.

The discovery of brilliant orange spessartine garnet in Namibia in 1991 created a sensation in the jewellery industry. In 1999, a new source was discovered in a remote area of Nigeria. Though this material was more yellow than the original find, the size and abundance of the crystals made the public more aware of, and increased the demand for, spessartine gems.

While spessartines of greater than 100 cts are known to have come from both Brazil and Madagascar, fine gems of more than 15–20 cts are rare. Mandarin garnets from Namibia scarcely yeild fine gems of greater than five carats.

With a hardness of 7.5 (out of ten) on the Moh’s Scale, the orange to reddish-orange shades of spessartine or mandarin garnet make for beautiful cut gemstones. They are widely used in jewellery and specimens from Tanzania are very popular among mineral collectors.