2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/177174[Fe/H] - phi_31 - log P relations are found for c-type RR Lyrae stars in globular clusters. The relations are analogous to that found by Jurcsik & Kovacs (1996) for field ab-type RR Lyrae stars, where a larger period correlates with lower metallicity values for similar values of the Fourier coefficient phi_31. The relations obtained here are used to determine the metallicity of field c-type RR Lyrae stars, those within omega Cen, the LMC and toward the galactic bulge. The results are found to compare favorably to metallicity values obtained elsewhere.6 pages, 9 figures. Accepted by MNRAS, major revision from previous versionAstrophysicstext