Malayaite
Malayaite is a calcium tin silicate mineral with formula CaSnOSiO4. It is a member of the titanite group. Discovery Malayaite was originally found in Perak (a state in Malaysia) and was first described in literature in 1961, though it was not yet given a name. In 1965, the mineral was named and recognized by the International Mineralogical Association. It was named for the locality in which it was discovered; which is the Malay Peninsula in Malaysia. Crystal structure and symmetry This mineral is classified under the nesosilicate group for silicate minerals because the titanite group falls under this category as well. Minerals in the nesosilicate group have isolated SiO4 tetrahedra connected to cations. In malayaite, the tetrahedra are connected to the chain of distorted SnO6 octahedra, in which the octahedra are linked by vertex [trans corners] sharing and form chains parallel to the miller index of [100]. Within the SnO6-SiO4 framework, the CaO7 polyhedra form chains parallel to [101]. Malayaite belongs to the monoclinic crystal system and has a 2/m (prismatic) crystal class. According to the Hermann–Mauguin notation, the '2' refers to the two-fold axis while the 'm' refers to the presence of a single mirror plane. The '/' symbol