adjective Mineralogy.

noting a shell-like fracture form produced on certain minerals by a blow.

Origin of conchoidal

First recorded in 1660–70; conchoid + -al1
Related formscon·choi·dal·ly, adverbsub·con·choi·dal, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for conchoidal

Historical Examples of conchoidal

British Dictionary definitions for conchoidal



(of the fracture of minerals and rocks) having smooth shell-shaped convex and concave surfaces
(of minerals and rocks, such as flint) having such a fracture
Derived Formsconchoidally, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

conchoidal in Science



Of or relating to a mineral or rock surface that is characterized by smooth, shell-like curves. Obsidian and quartz often have conchoidal fractures.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.