October birthstones: opal and tourmaline

How to read it

Opal is known for play-of-color, flashes of colour that move as the stone is turned, though not every opal shows it. Tourmaline comes in more colours than almost any other gem, often several in one crystal.

Also searched as: birthstone for October, opal birthstone, tourmaline birthstone.

When tourmaline became an October birthstone

The sources differ. The 1912 list, as George Kunz printed it, already names tourmaline as October's alternate stone; Jewelers of America's account, as National Jeweler reported it in 2016, lists tourmaline among the 1952 additions.