Another useful trick…
I’m making a pair of earrings, bezel set diamond in center with a
border of shared prong diamonds in a circle, with a field of black
enamel between center and circle. Black accentuates even the
slightest out of round in the diamond circle. Because its a pair they
have to exactly match, cuz you’ll see them side by side in the gift
box.
Mountings came out identical but once stones were set irregularities
showed up in the circles and one earring gave the impression of being
a tad large. We’re talking one and half pointers in the circle so a
coupla thousandths here or there really show.
Pulled out my round bezel blocks. Used a small hexagonal anvil, the
kind with numerous sized holes, as a backing to the earring(post in
anvil hole) and gently tapped the set earrings into the tapered hole
of the block. A reverse mandrel I suppose, squishing things into
alignment and reducing the large earring. Luckily outer row of prongs
prevented the girdles from contacting the block.
I wouldn’t try this with emeralds.