Ru-bīd'ĭ-ŭm, n.
n. [Lat. rubidus, red.] (Min.) An alkaline metal first found in mineral waters;—so called from exhibiting dark red lines in the spectrum analysis, by means of which it was discovered.
n. [Lat. rubidus, red.] (Min.) An alkaline metal first found in mineral waters;—so called from exhibiting dark red lines in the spectrum analysis, by means of which it was discovered.