Science: Crystal Culture

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Quartz crystals are harder to grow than the tenderest orchids. How nature does it is not exactly known, and nature does not produce enough big, perfect crystals to provide electrical manufacturers with the quartz slices they need to control radio frequencies, etc.

Early man-made quartz crystals were too small to be useful. During World War II the Germans did better, but not well enough. Last week Dr. Albert C. Walker of the Bell Telephone Laboratories told a gathering of scientists in Ithaca how Bell engineers had improved the German process until it grows quarter-pound crystals in only two weeks.

The Bell crystals are grown in thick-walled steel "bombs" filled with a water solution of alkaline material (see diagram). At the bottom is a layer of finely ground quartz (silica). A small quartz crystal (it may be only a sliver) is suspended near the top. When the bottom of the bomb is heated to 750°F., and the pressure raised to 15,000 Ibs. per sq. in., the ground quartz dissolves. Its molecules diffuse through the solution. When they reach the cooler top of the chamber, they deposit one by one on the "seed," building it into a perfect, transparent crystal which is more uniform, and therefore more useful, than any made by nature.