The present invention provides calcium salts of indole derived statins of the formula wherein R1 is alkyl, cycloalkyl or aralkyl; R2, R3 and R4 are independently hydrogen, halogen or alkyl; R5 and R6 are independently hydrogen, halogen, alkyl, cycloalkyl, aralkyl, alkoxy or aralkoxy; and the hydroxyl group at the 3-position is in the R-configuration and at the 5-position in the S-configuration; or an enantiomer thereof; or a hydrate thereof; as obtainable by the methods of the present invention. More specifically, the invention provides a calcium salt of formula IA wherein R1 is isopropyl, R2 is fluorine and R3, R4, R5 and R6 are hydrogen, designated herein as Fluvastatin calcium, in a highly crystalline form. Furthermore, the present invention is directed to methods for the preparation of the crystalline Fluvastatin calcium, and to pharmaceutical compositions comprising the crystalline form.