golden marcasite

Noun

golden marcasite (uncountable)

1. (obsolete) Zinc, due to colouring copper golden in admixture.
   • Another Sample from the same Mine, of a dusky reddish Colour, with an intermixture of Spar, and a brassy, or as it is call’d, the Golden Marcasite. Some Parts of this Body shine very finely, and are of a beautiful Colour, betwixt a Purple and Blue1729, John Woodward, An Attempt Towards a Natural History of the Fossils of England. […] Part I. Of the Fossils that are real and natural: Earths, Stone, Marble, Talcs, Coralloids, Spars, Crystals...
   • What still vastly increases the fusibleness of these Metals is the addition of Bismuth or Tin-glass, a Marcafite or Sulphureo-metallic substance, not so easily melted as Tin. That Bismuth Sir Isaac Newton used in these curious experiments, we shall just now have occasion to copy from him, did not...1740, George Martine, Essays medical and philosophical, London, page 364