  By codoping sulfur and copper into lead apatite, the crystal grains are
directionally stacked and the room-temperature resistivity is reduced from
insulating to $2\times10^{-5}~\Omega\cdot$m. The resistance-temperature curve
exhibits a nearly linear relationship at low temperature suggesting the
presence of strange-metal phase, and a second-order phase transition is then
observed at around 230~K during cooling the samples. A possible Meissner effect
is present in dc magnetic measurements. Further hydrothermal lead-free
synthesis results in smaller resistance and stronger diamagnetism,
demonstrating the essential component might be sulfur-substituted copper
apatite and the alkalis matter as well. A clear pathway towards
superconductivity in this material is subsequently benchmarked.
