protometals

from the GNU version of the Collaborative International Dictionary of English.

• noun plural A finer form of metals, indicated by enhanced lines in their spark spectra (which are also observed in the spectra of some stars), obtained at the highest available laboratory temperatures (Lockyer); as protocalcium, protochromium, protocopper, protonickel, protosilicon, protostrontium, prototitanium, protovanadium.