  The nature of $\iota/\eta(1440)$ is analysed in the framework of the
hypothesis that it represents a single pseudoscalar resonance. Assuming that it
arises due to the mixing between the glueball and the $q\bar q$ nearby states
($\eta$, $\eta'$, and their radial excitations) two upper estimates are
obtained for the partial width $\Gamma(\iota/\eta(1440) \to K^* K)$ --- one for
the case when $\iota/\eta(1440)$ is mainly a glueball and another one when it
is mainly a radial excitation of the $s\bar s$ state. Both estimates are
obtained in the chiral perturbation theory approach taking into account the
available data on the vector mesons and the pseudoscalar state K(1460), which
is interpreted as a radial excitation of the $K$ meson. The same partial width
is independently estimated on the basis of the combined OBELIX and Crystal
Barrel data on the production of $\iota/\eta(1440)$ in $p\bar p$ annihilation.
Comparing the results we show that the glueball content of $\iota/\eta(1440)$
is suppressed while its $s\bar s$ radial-excitation interpretation is favoured
by the data.
