aventurine

noun

1. (countable, uncountable)A kind of brownish glass containing gold-coloured spangles.

   “Aventurin or avanturin glass was formerly made only in the Island of Murano, near Venice, but is now prepared throughout Germany, Italy, Austria, and France. It is a brown glass mass in which crystalline spangles of metallic copper according to [Friedrich] Wöhler (of protoxide of copper according to [Max Joseph] von Pettenkofer) appear dispersed. [...] The Bavarian and Bohemian glass-houses produce an aventurin glass rivalling the original.”

2. (broadly, countable, uncountable)A variety of translucent quartz, spangled throughout with scales of yellow mica.

   “The Sandaresus, an Arabian stone, classed by Pliny [the Elder] among the Carbunculi, seems to have been our Aventurine, for he describes it as full of golden stars shining through a transparent substance, not from the surface, but from within the body of the stone. The true Aventurine, or Goldie-stone, is a brownish semi-transparent quartz, full of specks of yellow mica.”

   “[F]rom out the silken curtain-folds / Bare-footed and bare-headed three fair girls / In gilt and rosy raiment came: their feet / In dewy grasses glisten'd; and the hair / All over glanced with dewdrop or with gem / Like sparkles in the stone Avanturine.”

   “During this period of two centuries little colour was employed in the lacquer-work, but much gold was used; and those particular kinds of work in which "clouded" gold effects, avanturines, and tesselated gold are introduced, as well as low-relief modelling of a most perfect kind, were invented and brought to a high state of perfection.”

   “Quartz with spangled inclusions is known as aventurine. The included minerals are scales of shiny mica or hematite. The most familiar aventurine is of a reddish-yellow color and has a coppery sheen. Only small quantities of aventurine have been found in the United States.”