This material has a dull luster and a Conchoidal fracture.
"The Economic Aspect of Geology"
C. K. Leith
The final stage of coal formation is anthracite,-hard, brittle, black, with high luster and Conchoidal fracture.
"The Economic Aspect of Geology"
C. K. Leith
In nine or ten miles to the north of Boorbarna, we crossed a curious tract of country, covered with what I considered a variety of quartz, which breaks with a Conchoidal fracture, but it has very much the appearance of flint; in many places the pieces were large, with sharp angles; my sons complained that it injured their horses' feet, but by alighting, and leading our horses over the worse parts, I did not perceive any bad effects from it.
"The Bushman Life in a New Country"
Edward Wilson Landor