What metal impurity makes rubies red and emeralds green?

More Questions:

According to Pliny the Elder, what word do we get from the Roman practice of paying soldiers in salt?

What is the subtitle of the traditional version of the board game "Monopoly"?

What restaurant is known as Mai Dang Lao in China?

Which literary work's title character is named Oliver Mellors?

Which Harry Potter character is part-giant?

Which of the New England states is the largest in size?

What US city is home to the Bishop Museum?

What is the Capital of Guadeloupe?

The Gadsden Purchase involved the lower portions of what are now which two US states?

The Republic of Upper Volta was the official name of which African country before August 1984?

What is a group of apes called?

Robert Leroy Parker was better known as who?

What brainchild of Wisconsin senator Gaylord Nelson was first celebrated on April 22, 1970?

The "Indus Valley Civilization" is also known by what other name?

Who sang the song "Un-Break My Heart"?