Protometals

Pro`to`met´als


n. pl.1.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.
Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.