platinum vs silvern

platinum

adj
  • Of a whitish grey colour, like that of the metal. 

  • Of a musical recording that has sold over one million copies (for singles), or two million (for albums). 

  • Very expensive, or of very high quality 

noun
  • A single or album that has achieved platinum sales, i.e. over 1 million or 2 million. 

  • A whitish grey colour, like that of the metal. 

  • A platinum-based drug: a platin. 

  • The chemical element with atomic number 78 and symbol Pt; a dense, malleable, ductile, highly unreactive, silverish-white transition metal of great value. 

verb
  • to reach platinum level in a game 

silvern

adj
  • Made of silver; or resembling or characteristic of silver; silvery. 

How often have the words platinum and silvern occurred in a corpus of books? (source: Google Ngram Viewer )