Definition of "bluestone" [blue•stone]

• A bluish-gray sandstone used for paving and building. (noun)
• A stone similar to this kind of sandstone. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Destruction by poisoning is accomplished by inoculating the thick leaves with arsenic or bluestone, which is sprayed upon them after the plants have been hacked so that the poison may be absorbed by the sap, which distributes the deadly substance."
• "South African cooks were accused of putting "bluestone" (or copper sulfate) in Army food."
• ""bluestone" with which its fiery contents were strengthened, would work the passionate natures, on which it was to play, up to the proper crime-committing pitch."