corundum
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Diamond defines a hardness of 10 and is actually about four times harder than corundum, which is 9.
From Textbooks • Jan. 1, 2017
The Bronco mane and eyeball were created from orange sapphires while the head features pave-set diamonds and custom-cut corundum blue stone.
From Washington Times • Jun. 12, 2016
Some of these minerals may very well be our very own corundum, with its trace elements.
From Scientific American • Apr. 14, 2012
Diamonds are a 10 and almost four times harder than corundum.
From BusinessWeek • May 31, 2011
How to Point a Pencil.—Rub the pencil to a point in the groove of a corundum file.