Gugiaite
Gugiaite is a melilite mineral, named for the Chinese village of Gugia where it was first discovered. Its chemical formula is Ca2BeSi2O7 It occurs mostly in skarns with melanite adjacent to an alkali syenite and has no economic value. Its crystals are small tetragonal tablets with vitreous luster and perfect cleavage. It is colorless and transparent with a density of three. The mineral belongs to space group P-421m and is strongly piezoelectric.