Sentence Examples


  • Obsidian and rock crystal were also used for knife making.
  • Breakfast was on the magic obsidian tray next to the bed.
  • Few obsidians are entirely vitreous; usually they have small crystals of felspar, quartz, biotite or iron oxides, and when these are numerous the rock is called a porphyritic obsidian (or hyalo-liparite).
  • Large areas are overlain with trachyte, basalt, obsidian, tuff and pumice.
  • The volcanic series include the rhyolite of Nell Island, some obsidian, and the sheets of basalts which form the Cloudy Mountains, Mount Dayman and Mount Trafalgar (an active volcano), and also cover wide areas to the south and west of the Owen Stanley Range.