Peter Singer

In 1967, the world health community launched a global effort to eradicate smallpox. It took a coordinated, worldwide effort, required the commitment of every government, and cost $130 million dollars. By 1977, smallpox had disappeared.

The price of diamonds can vary greatly depending on size, cut, color, and other factors, including whether they have a history. But because of the rarity of blue boron diamonds, they often fetch more money than gems of similar quality.