Spessartine is a mineral with a hardness of 7 out of 10 on the Mohs scale of mineral hardness [?]. These Cubicly structured gems are made of manganese aluminum silicate, their full chemical compound being Mn3Al2(SiO4)3.

Spessartine is the manganese-aluminum variety of Garnet, belonging to its sub-group of aluminum garnets. Garnets are a group of silicate minerals that all crystallize in the isometric system and have the same chemical formula, but in a diversity of proportions, so garnets show up as different varieties, in a broad range of environments.

Spessartine possesses the form typical of garnet crystals, which are usually isolated, well-formed, rhombic dodecahedral 12-faced specimens. It may be semiopaque or transparent, and has no cleavage. Transparent crystals display an attractive luster.

This lustrous gem can be found in a range of colours: red, reddish orange, orange, yellowish brown, reddish brown, yellow and pink. Nigerian stones tend to have a darker hue and may range from very deep, dark, pure red to rich, deep golden orange with a touch of fiery red, or intense reddish orange and deep reddish orange or burnt orange.

The brilliant fire-red/"aurora-red" to orange-yellow color, caused by the content of manganese, make it one of the loveliest members of the garnet group, and can call to mind the blaze of a raging sunset.

Though garnets are found in a wide range of occurrences, the spessartine variety is found almost exclusively in manganese-rich granites, pegmatites, or metamorphic rocks. Crystals, sometimes as large as 7cm. in diameter, were found from the tourmaline pegmatites of San Diego County, California (USA). Spessartine of cutting quality is extracted from the gem gravels of Sri Lanka, upper Burma, Mexico, Italy, Tanzania, and Madagascar.

So far spessartine has also been found in Brazil, central India, Australia as well as in Kenya, Nigeria, in the Kunene River, Namibia. It was in the Rutherford mine in Amelia County, Virginia (USA) that a specimen weighing more than 2,800 carats was found, which was afterwards called the Rutherford Lady.

Other occurrences include: the LeChang Mine, Guangdong, China; the North-west Frontier Province, Pakistan, such as the Shigar Valley, Skardu; Nepal and Nuristan, Afghanistan.

Spessartine is also found as inclusions in topaz.

It is also spelled as "spessartite," which is also its rock form, and as "fireball garnet."

Color varieties/trade names of spessartine include:

Malaya (Malaia) Garnet – an intermediate variety between spessartine and pyrope, the red garnet. The colour of malaya varies from orange, red-orange, peach and pink.

Manila garnet – a yellowish-orange garnet variety from Manila (Philippines) consisting mainly of pyrope and spessartine, which exhibit different colors in daylight and incandescent light.

Mandarin, Hollandite or Kunene spessartine – name given to spessartine from the original mine in Kunene, Namibia. The samples with a rich orange colour was first called hollandite but eventually this was surpassed by the name 'mandarin' probably for its similarity in hue to mandarin orange pulp. This variety is a near end-member of the species, seen in its intense orange colour. Most of the material is clear and transparent, although larger stones appear to have veils which can give polished specimens a foggy look.

Kashmirine – the name given for orange-red spessartine mined in the Neelum valley in Kashmir, Pakistan.

The specific gravity [?] for Spessartine is 4.16, its refractive index [?] is 1.79-1.81, and its double refraction [?] is None.