The chemical formula of mineral Cattiite is indicated by Mg3(PO4)2•22(H2O). This mineral commonly occurs in cavities in a dolomite carbonatite vein that cuts forsterite-magnetite ore. Cattiite is usually found at its type of locality at Zhelezny Mine Kovdor massif, Kola Peninsula, Russia. Cattiite was named for Michele Catti, Professor of Physical Chemistry, University of Milano Bicocca, Italy. Mineral Cattiite is known to crystallize in the triclinic system of crystal formation. In optical mineralogy, this triclinic crystal system commonly comprises crystals having three axes, of which all are unequal in length and are positioned oblique to one another. Cattiite is usually found showing perfect cleavage in one direction when viewed with the aid of polarized microscopes. Cattiite is usually found colorless in hand sample. The density measure of mineral Cattiite is usually found 1.65 grams per cubic centimeters. Most crystals of mineral Cattiite are found transparent in appearance. Cattiite is commonly found showing uneven fracture. These are flat surfaces (not cleavage) fractured in an uneven pattern. Mineral Cattiite is also usually found massive to granular in form. This is a common texture observed in granite and other igneous rock. The hardness measure of mineral Cattiite is usually found 2 when evaluated using the Mohs scale method. Mineral Cattiite is usually found showing vitreous or glassy luster when evaluated in reflected light of polarizing microscopes. Mineral Cattiite is commonly found showing white streak when rubbed on white poprcelain streak plate. Cattiite is also found showing biaxial negative figure when evaluated between crossed nicols of polarizing microscopes. Cattiite is also found showing 0.0110 birefringence. Cattiite is found to be not radioactive.