amethyst vs damson

amethyst

adj
  • Having a colour similar to that of the gemstone 

noun
  • A purple colour. 

  • The tincture purpure, when emblazoning the arms of the English nobility. 

  • A transparent purple variety of quartz, used as a gemstone. 

damson

adj
  • The color of the fruit of this tree, a very deep purple. 

noun
  • A subspecies of plum tree, Prunus domestica subsp. insititia, native to Eurasia. 

  • The edible fruit of this tree. 

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