Union
According to line 273, "union" is another word for pearl.
Because Hamlet says to Ophelia "Get thee to a nunnery: why wouldst thou be a breeder of sinners?" It's just a convenient term to identify the scene because it's such a memorable and striking line. It could just as easily be called the "To be or not to be" scene but that's more of a mouthful.
"Baroque" is a pearl that is not round.
Siloquy
I think the term you are referring to is "Tahaition Black Pearl". Bill Warren www.hudsongoldmine.com I think the term you are referring to is "Tahaition Black Pearl". Bill Warren www.hudsongoldmine.com
The common term would be "CUT!" .
From French, it means "placed in a scene" or "placed on stage." It is a dramatic term for the visual setting of a scene.
Metafiction
A pearl is not extracted from the earth. They are found in oyster's shells. The term for it is harvesting oysters.
"oddly shaped pearl" or "Misshapen pearl"
Another term for partial print is latent.
mise en scene -placing scene,costumes on stage for theatrical production