The shank varies with the size of the stone.
my 6.5mm Celeste from AD measures (the shank, before the cathedral shoulders begin) just under 2mm tall, and the bottom of the shank (palm side) is about 1.3mm thick.
that's height of the metal up off the finger. it's about 3.5mm wide at the top, and about 2.5mm wide on the palm side.
here's my ring (rose gold, 1ct center Asha OEC, sz 8) right after i got it, before i took the tag off:
i love the Celeste setting.