Correct spelling for the English word "Magneticalness" is [maɡnˈɛtɪkə͡lnəs], [maɡnˈɛtɪkəlnəs], [m_a_ɡ_n_ˈɛ_t_ɪ_k_əl_n_ə_s] (IPA phonetic alphabet).
The quality of being magnetic.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.