Andalusite is a mineral with a hardness of 8 out of 10 on the Mohs scale of mineral hardness [?]. These Orthorhombicly structured gems are made of lead sulphate, their full chemical compound being Al2SiO5.

The gem Andalusite is a gemstone composed of Lead Sulphate giving it a yellowish hew with a light tint of a rusty red color. Its named after the city Andalusia in Spain where it was first found.

Colors generally vary from yellow, to yellow green, to green, to brownish red (more iron in the read hued versions), to purple, and even black. This gem is pleochroic meaning it changes color depending on the direction and angle you are looking at it from.

Andalusite can be found in Australia, Brazil, Germany, Russia, and of Spain. Minor deposits have been found in other countries like Canada the United States. If you are looking for the best crystals however check in Morocco, and Namibia.

The specific gravity [?] for Andalusite is 3.16, its refractive index [?] is 1.63-1.64, and its double refraction [?] is 0.01.