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

This crystalline aluminum mineral is called corundum, and people have been wearing it with pride for thousands of years.

From Scientific American • Apr. 14, 2012

Diamonds are a 10 and almost four times harder than corundum.

From BusinessWeek • May 31, 2011

The hardness of emery is about 8, whereas that of pure corundum is 9.

From Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 3 "Electrostatics" to "Engis" by Various