(n.) 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.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). Pearlstone. Retrieved September 25, 2026, from http://smartdefine.org/pearlstone/definitions/2042922 |
| Chicago | Webster's. 2011. "Pearlstone" http://smartdefine.org/pearlstone/definitions/2042922 (accessed September 25, 2026). |
| Harvard | Webster's 2011, Pearlstone, Smart Define, viewed 25 September, 2026, <http://smartdefine.org/pearlstone/definitions/2042922>. |
| MLA | Webster's. "Pearlstone" 27 May 2011. Web. 25 September 2026. <http://smartdefine.org/pearlstone/definitions/2042922> |