Metallicity spread (Δ[M/H]) and dispersion (σ_[M/H]) versus the mass of the GCs (Baumgardt & Hilker 2018). The metallicity spreads (top left) are for the P1 stars as presented in Sect. 4.1. The other panels show the metallicity dispersions for the P1, P2, and P1+P2 stars. Our data points are color-coded by the average metallicity of the cluster (Harris, 2010 edition). The gray squares in the bottom-right panel represent the σ_[Fe/H] taken from the literature compilation of Bailin (2019) for the GCs in common with our study. The gray downward triangle indicates the upper limit on σ_[Fe/H] measured for NGC 6362.