Welcome to our extensive antique jewelry glossary with around 1,500 jewelry related entries.If you feel you are missing an explanation, feel free to let us know and we will add it.
The quality of some gemstones (e.g. corundum) that makes it possible for them to split only along certain definite planes (e.g. some twinning planes) of the crystal, contrary to cleavage which leads to splitting anywhere parallel to the cleavage plane.
From: An Illustrated Dictionary of Jewelry, autor: Harold Newman, publishers: Thames and Hudson