The name Opal is believed to have originated in India (the source of the first opals brought to the Western world), where in Sanskrit it was called upala, meaning “precious stone”. Opals are divided into three subgroups: precious opals (white, black boulder, etc.), yellow to red fire opals, and common opals (usually opaque with no play of color). Most opals are valued for their shifting colors in rainbow hues. The opal birthstone can be found in many places. Australia is the most productive in the world. New South Wales is famed for producing the black opal and the boulder opal only comes from Queensland. Opals range from 5 to 6.5 on the Mohs Scale of Hardness. Opal is also the stone given to celebrate the 14th wedding anniversary.

Tourmaline is the newer October birthstone. The name comes from the Sinhalese word toramalli, which means “stone with mixed colors,” because it often multi-colored. Tourmaline colors include: pink, red, yellow, green, brown, blue, violet, and black. The most popular colors are pink and green. The tourmaline birthstone is rated 7 to 7.5 on the Mohs Scale of Hardness. These colorful gems are usually stable enough to withstand light and most chemicals, but heat can be damaging. It is also the 8th wedding anniversary gemstone.

Both October birthstones are best cleaned with warm, soapy water and a soft brush.