{110} and {001}. Cleavages are on {100} good, and {010} distinct. Physical properties Zanazziite is usually pale green and occasionally dark green. It is a 5 on the Mohs hardness scale. Optically biaxial +, ex = 1.606, 13 =1.610, "y = 1.620, 2V, = 72°(65° calc) X = b, Z:[100] 3° in obtuse 13; and the density = 2.76 measured, 2.77 calculated. Zanazziite has a vitreous luster, slightly pearly on the cleavage surfaces. Its cleavage is {100} good, {010} distinct. Zanazziite is nonfluorescent in longwave or shortwave ultraviolet light. Zanazziite also shares many physical properties with roscherite. Geologic occurrence The roscherite analog zanazziite was found in Lavar da Ilha deposits in Minas Gerais, Brazil. Zanazziite grows usually along the surface of quartz minerals. It occurs in pegmatite in beds of the Jequitinhonha river valley. The pegmatite consists of a wall zone rich in feldspar and muscovite, and a quartz core. The core margin has small pockets and crevices which contain quartz crystals and a number of phosphate minerals (on which the roscherite minerals accumulate). This is special to quartz and phosphate due to the rich locality of Minas Gerais. Minas Gerais contains the world's most diverse concentration of complex granitic pegmatites. This region is responsible for the production of gem beryl, chrysoberyl, topaz, tourmaline, and kunzite. See also List of minerals List of minerals named after people References Calcium minerals Magnesium minerals Iron minerals Manganese(II) minerals Aluminium minerals Beryllium minerals Phosphate minerals Monoclinic minerals Minerals in space group 15