Opal

The October birthstone’s dramatic play-of-color has inspired writers to compare it to fireworks, galaxies and volcanoes.

 Ranges from 5 to 6.5 on the Mohs Scale
The opal birthstone can be found in many places. The fields of Australia are the most productive in the world for the October birthstone. Ethiopia, Mexico and Brazil are also important sources. Additional deposits have been found in Central Europe, Honduras, Indonesia, Madagascar, Peru, Turkey and the United States.

Tourmaline

Tourmaline is the newer October birthstone.

The name comes from the Sinhalese word toramalli, which means “stone with mixed colors,” because it often has multiple colors in one crystal. Very few gems match tourmaline’s dazzling array of colors.
Among the most popular are the pink and red rubellites, the emerald green “chrome” tourmalines, and the neon green and blue-to-violet “paraíba” tourmalines.
The tourmaline birthstone is rated 7 to 7.5 on the Mohs scale of hardness and is generally suitable for everyday wear