October birthstones

October birthstones: Opal and Tourmaline

October has two birthstones: Opal and Tourmaline. Both GIA and the American Gem Society list both.

Opal

A gem whose play of color comes from tiny silica spheres that diffract light. Opals with this effect are called precious opals. Opal holds 3 to 21 percent water.

Colors: Rainbow play of color; Described by body color: black or white
Mohs hardness: 5 to 6.5
Everyday wear: Delicate
Found in: Australia (about 95 percent of world supply since about 1850), Mexico, Brazil, Honduras

The Roman scholar Pliny wrote about opal's shifting rainbow colors.

Opal meaning, colors and care →

Tourmaline

A family of related minerals that comes in more colors than almost any other gem. It can become electrically charged when heated or squeezed.

Colors: Pink; Red (rubellite); Green (verdelite, chrome tourmaline); Blue (indicolite)
Mohs hardness: 7 to 7.5
Everyday wear: Wear with care
Found in: Brazil, Sri Lanka, Nigeria, Mozambique

Tourmaline meaning, colors and care →

Which October birthstone should you choose?

Pick by color, budget and how the piece will be worn. Harder, tougher stones suit rings worn every day; softer ones last longer as pendants or earrings.

Stone	Mohs	Everyday wear	Warm soapy water	Ultrasonic
Opal	5 to 6.5	Delicate	The only safe method	Not safe (GIA: warm soapy water is the only safe way)
Tourmaline	7 to 7.5	Wear with care	Safe (the best method)	Not recommended

Compare: Opal vs Tourmaline

October birthstone gift ideas

The right piece depends on how tough the stone is. These suggestions follow GIA's hardness and toughness notes for each stone.

Stone	Best as	Why
Opal	Pendants and earrings for occasional wear	Soft or easily damaged. Skip everyday rings and bracelets, which take the most knocks.
Tourmaline	Pendants and earrings, or a protected ring	Can chip or scratch, so a pendant or earrings is the safer gift. For a ring, choose a protective bezel setting and occasional wear.

For a mom: a pendant or bracelet with each child's birthstone. Mix tougher stones with delicate ones only in pendants.
For a partner: stud earrings or a simple pendant in her own stone are easy to wear with anything.
Before you buy: ask whether the stone has been treated, and get it in writing. Treatments change how a stone should be cleaned.

See every month in our birthstone gift guide by month.

Traditional October birthstones

Before the US list was standardized in 1912, the traditional stones for October were: Opal, aquamarine. How the list changed.

Caring for Opal and Tourmaline

Opal: warm soapy water: the only safe method; ultrasonic: not safe (gia: warm soapy water is the only safe way); steam: not safe (gia: warm soapy water is the only safe way). Details
Tourmaline: warm soapy water: safe (the best method); ultrasonic: not recommended; steam: not recommended. Details

Frequently asked questions

What is the October birthstone?

Opal and Tourmaline. A gem whose play of color comes from tiny silica spheres that diffract light. Opals with this effect are called precious opals. Opal holds 3 to 21 percent water.

What color is the October birthstone?

Opal: rainbow play of color. Tourmaline: pink.

Why does October have 2 birthstones?

Extra stones were added to the US list by jewelry trade groups to give more choice of color and price (in 1952, 2002 and 2016).

Is the October birthstone durable?

Tourmaline is 7 to 7.5 on the Mohs scale (wear with care). Opal is 5 to 6.5 on the Mohs scale (delicate).

Sources: American Gem Society: Birthstones, GIA: The Beauty of Birthstones, and the GIA care guide and AGS overview for each stone (linked on its page). Checked October 16, 2026.