Robert Eakins, age 12, of Manteno, Ill., for question:

Is chrome mined?

Nowadays, chrome is the everyday word for the hard, silvery metal used to plate car bumpers and bathroom fixtures. The full name for the sturdy metal is chromium and as such it rates as one of the basic chemical elements. It heads column six of the Periodic Table. There you can see at a glance that it resembles two other sturdy metals, molybdenum and tungsten. In nature, it occurs in the ore chromite which is s. compound of chromium, iron and oxygen. It also occurs in crystal form, sometimes lens‑shaped and sometimes shaped like a pair of neat pyramids set base to base.

The name chromium comes from a Greek word meaning color, but not because the mirror surface of the bright metal can reflect the colors of the rainbow. It is named for the colorful compounds it forms with other elements. Chromium and lead form a lovely .yellow compound, chromium and potassium form a vivid red. With zinc it forms a different red compound, with barium it forms a lemon yellow, For more than 100 years after its discovery, chromium was used mainly to make artists= colors. Some was used in the tanning of leather.

Before World War I, the only chromite mine in the world was in Maryland. There, the heavy, black ore was mined to make the colorful compounds called chromates and for tanning. The pure metal is very hard to extract from the ore and no one guessed that the effort was worthwhile, Then, terrific heat was applied to the ore and the chromium and iron smelted to form a metal alloy.

Later, pure chromium was separated from its ore by electrolysis, by means of an electrolytic cell and a powerful electric current. The chromium mixture is made into a solution and placed in a tank.

The solution is connected to the current by two electrodes which dip into the bath, one at each end. The current separates the pure chromium from the unwanted impurities. The pure metal collects on one of the electrodes.

With this process, chromium metal was able to come into its own and take its rightful place with iron and copper, aluminum and tin, nickel and lead, Chromium is a hard and sturdy metal. It resists rust and many acids. It can withstand terrific heat, pressure and shock. It contributes these sturdy qualities when alloyed with other metals. The durable metal we call stainless steel is an alloy of steel containing from 14.% to 18% of the metal chromium.

The chromite mine of Maryland is no longer the only one in the world, though no rich ores of this mineral ever have been found. Most of the United States supply of chromium comes from a low grade ore mined in Montana, There are other deposits in California, Wyoming, New Jersey and Pennsylvania, all of them buried in masses of lava rock. Chromites the only ore of chromium, is a black, waxy mineral often streaked with brown.