Answers are grounded in this paper and cite their sources.
The mist zone, the arc of stippled surface surrounding the mirror-smooth area at the origin of fracture, was examined in detail using an optical microscope and progressive etching. The results show that the stippled area can be regarded as a collection of large numbers of individual local elements of but two basic types, and that microscopic cracks exist below the fracture surface which are related to the structure on the exposed surface.
No takes yet. Share an insight, caveat, or question.
Johnson et al. (1968) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: