Pearlstone

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Pearlite \Pearl"ite\, Pearlstone \Pearl"stone`\, n. (Min.)
     A glassy volcanic rock of a grayish color and pearly luster,
     often having a spherulitic concretionary structure due to the
     curved cracks produced by contraction in cooling. See Illust.
     under {Perlitic}.
     [1913 Webster]