What is the hardness of a ruby on the Moh's hardness scale?

A ruby is a mineral corundum. The Mohs hardness scale lists the following from softer to harder:

Talc - 1

Gypsum - 2

Calcite - 3

Fluorite - 4

Apatite - 5

Feldspar - 6

Quartz - 7

Topaz - 8

Corundum (which includes the ruby) - 9

Diamond - 10

Ruby has a Mohs hardness of 9.