this x ray diffraction pattern is characteristic of all the species of zsm 23 compositions ion exchange of the sodium ion with cations reveals substantially the same pattern with some minor shifts in interplanar spacing and variation in relative intensity other minor variations can occur depending on the silicon to aluminum ratio of the particular sample and on whether it has previously been subjected to thermal treatment while synthetic zsm 23 zeolites may be used in a wide variety of organic compound conversion reactions they are notably useful in the processes of polymerization aromatization reforming esterification and cracking other hydrocarbon conversion processes for which zsm 23 may be utilized in one or more of its active forms include for example hydrocracking and converting light aliphatics to aromatics such as disclosed in u s pat no 3 760 024 synthetic zsm 23 zeolites can be used either in the alkali metal containing form the alkali metal form and hydrogen form or another univalent or multivalent cationic form they can also be used in intimate combination with a hydrogenating component such as tungsten vanadium molybdenum rhenium nickel cobalt chromium manganese or a noble metal such as platinum or palladium where a hydrogenation dehydrogenation function is to be performed combinations of the aforenoted metals may also be used such components can be exchanged into the composition impregnated thereon or physically intimately admixed therewith such components can be impregnated in or on to zsm 23 for example by in the case of platinum treating the zeolite with a platinum metal containing ion thus suitable platinum compounds for this purpose include chloroplatinic acid platinous chloride and various compounds containing the platinum amine complex combinations of metals and methods for their introduction can also be used m can be one or more of a variety.