Abstract: The present invention relates to a microporous crystalline material of zeolitic nature, called ITQ-1A, to the process for its preparation and its use in processes of separation and transformation of organic compounds. In the roasted and anhydrous stage, the chemical composition of the material corresponds to the empirical formula: x(M.sub.1/n XO.sub.2):yYO.sub.2 :SiO.sub.2, wherein x has a value smaller than 0.02 and may equal 0: y has a value smaller than 0.04 and may equal 0: m is H.sup.+ or an inorganic cation with the charge +n: X is a chemical element with an oxidation status +3 (Al, Ga, B, Cr) and Y is a chemical element with an oxidation status +4 (Ti, Ge, V). When x=0 and y=0, the material may be described as a new polymorphe form of microporous silica. The material of this invention is characterized also by its X ray diffraction pattern.