Number 20 (Story #1), February 5, 1991 by Phillip F. Schewe and Ben Stein HYDROGEN REDUCTION OF RUBY may complicate the search for metallic hydrogen, which usually proceeds by placing a small sample of molecular hydrogen between the faces of a diamond anvil. Since these faces are very close together scientists sometimes add a small amount of ruby powder (Al2O3) to the hydrogen in an effort to reduce the resultant interferometric fringe pattern. Arthur Ruoff at Cornell (607-255-4161) has shown that at high pressures, hydrogen reduction of ruby produces the metal aluminum. This would confound an unambiguous measurement of metallic hydrogen. (Upcoming article in Physical Review Letters.)