Philistine
backed
brazen
calcified
callous
calloused
case-hardened
conscienceless
crusted
crusty
crystallized
flinty
fossilized
granulated
hard
hardened
hardhearted
heartless
hornified
impervious
incrusted
indurate
insensitive
inured
lapidified
lost to shame
obdurate
ossified
pachydermatous
petrified
proof against
reinforced
rigidified
sclerotic
seared
set
shameless
solidified
steeled
steeled against
steely
stiffened
stony
strengthened
thick-skinned
toughened
unblushing
vitrified