“The Case of the Barnacled Crystal”, 1950 (; backlinks; similar):
[Bell Labs account of a bizarre chemical problem.
Bell manufactured in substantial volume ethylene diamine tartrate (EDT), a piezoelectric synthetic crystal, which it used as a substitute for scarce quartz in telephone line components. While the crystals were usually easy to grow, simply by slicing up crystals and dunking them in solutions, new crystals were sprouting a different EDT crystal, a kind of crystal which grew well in the existing solution and solutions prepared from scratch and solutions made from the new crystals as well, yet was completely worthless. This had happened despite no changes in the manufacturing process.
Investigation revealed the new crystal was in fact EDT, but a kind with an additional water molecule. This kind was more stable at lower temperatures than the original, and the manufacturing happened to be done slightly under the critical crossover point—and the ‘superior’ EDT form had finally spontaneously happened and now infected all manufacturing. (Because of the instability, any contact with moisture, such cutting crystals with water jets, would make the new form “sprout like fungus growth”.)
The solution was to eliminate moisture as much as possible, and start manufacturing at temperatures above the crossover point, where the new kind is disfavored.]
View PDF: