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Two Choices for October, the Opal and the Tourmaline

Updated: Oct 29, 2022

People born in October have the choice of two birthstones, the Opal and Tourmaline. Both come in a rainbow of shades and color combinations. In fact, according to legend, both of October’s birthstones came to earth through a journey involving rainbows.

The Opal is the first of the Birthstones of October and is the stone that is used to celebrate the 14th year of marriage.

The Opal has tightly packed silica spheres that refract light giving it a play of color called opalescence. A display of rainbow-like hues that can be seen when viewed from different directions.

The name "opal" originates from the Greek word opallios, which means “to see a change in color”. When Australia’s mines began to produce opals commercially in the 1980’s it quickly became the worlds primary source for this October birthstone.

The Tourmaline is the second of October’s birthstone choices as well as the gift for the eighth wedding anniversary.

The word tourmaline is thought to come from the Sinhalese word, “turamali” which means “stone with various colors” in reference to its extreme versatility. The Tourmaline’s colors are dependent upon the different elements in the chemical makeup.

Physical Properties

The Opal:

The opal is a soft stone with a Mohs hardness of 5.5 – 6.5, so one must be careful with polishing and storing this delicate gem.

Boulder Opal, rough

In the 1960's scientists used an electron microscope to analyze the structure of an opal. It was discovered that small spheres of silica gel caused the interference; refraction and diffraction of light, resulting in the opal’s distinctive play of color.

Opals consist of tightly packed silica spheres with water trapped between the spheres. Opals can dry out over time, so keeping a damp cloth in a tightly sealed bag with your opals is a good way to keep the moisture content intact.

In Australia "the formation process [of opals] began about 140 million years ago. At that time, an inland sea, abundant with silica-rich sands, covered much of central Australia. Around 30 to 40 million years ago, heavy weathering began to dissolve the silica. The holes that were formed in the rock began to collect silica-rich water." Over time, the silicates trapped in these spaces formed opals.

The Tourmaline:

There are a variety of elements that help create the various colors of tourmalines. It is

generally agreed that traces of iron, and possibly titanium, induce green and blue colors. Manganese produces reds and pinks, and possibly yellows. Some pink and yellow tourmalines might owe their hues to color centers caused by radiation, which can be natural or laboratory-induced.

The tourmaline is a little harder with a Mohs of 7.0 – 7.5. It forms in the trigonal system and has a three-sided prism, like no other common mineral. Tourmalines are also dichroic to some degree, meaning the gems appear to have different colors from different viewing angles. Dichroism describes the crystalline structure and trace minerals that make up the different colors of this versatile gem. The light beams are split through the gem and register to the human eye as different colors.



Opals were prized by the Romas as early as 250 BC, and they got their opals from Eastern Europe at the time. It wasn't until the 1800's that the Opal gained worldwide popularity.

Australia became the main producer of opals since they were re-discovered there in the 1850’s.

Tullie Cornthwaite Wollaston, ca.1920

Tullie Cornthwaite Wollaston took 60 brilliant pieces of opal rough mined in Queensland to London in July of 1889. Despite initial rejection from dealers, he persisted and finally sold the stones to an international jewelry firm. And thus began the European love affair with the opal.

Australia is the leading supplier of all opals; 95% of mined opals come from Australia. Since the 1850s, smaller deposits have been discovered in Brazil, Ethiopia, Indonesia, Japan, Mexico, Russia and the states of Idaho and Nevada. Though all opals are beautiful, the deep blue and green variations from Australia are, in my opinion, the most beautiful.


It is thought that the tourmaline was mined and used as a gemstone as early at the 1500s but was mistaken for a variety of other other precious stones. Some early tourmalines may have been confused with the emerald, pink topaz, ruby and fancy sapphires, to name a few. It wasn't until the 1800’s when its chemical composition was documented and it was discovered that the tourmaline is a unique gem.

In 1892, George Kunz, an American mineral collector, introduced the green tourmaline from the Mount Mica mine in Maine to Tiffany & Co., which sparked an interest in tourmaline and led to its popularity.

Tourmaline mines discovered in Brazil in the 1980's and 1990's brought new enthusiasm to the jewelry industry with bright new hues.

Tourmalines can be found in pegmatites and alluvial deposits all over the world. Tourmaline is also the national gemstone for the United States where it has been mined for centuries. Up until the early 1900’s, the US was considered the primary source for fine tourmalines. Today, the most significant deposits are found in Brazil. There are also deposits found in Australia, Burma, Mozambique, Russia, Sri Lanka and many countries in Africa.

The Paraiba Tourmaline is one of the most beautiful, rare and expensive of the colored tourmalines. In the 1980s the Jose de Batalha mine in the Brazilian state of Paraiba began producing a tourmaline with a color like no other. The deposit has been almost mined out and there are few gems left, which has bolstered prices to new highs. The “Ethereal Carolina Divine Paraiba” is the largest Paraiba tourmaline and was set into a one-of-a-kind necklace by Canadian Jewellery house Kaufmann de Suisse. I personally think the Paraiba Tourmaline is one of the most vibrant of the gemstones, aptly named the Neon Tourmalines.

Some other more popular trade names for tourmalines include the pink-red rubellite, blue-green indicolite, and the bi or tri colored tourmalines. The market will also use descriptive names such as yellow tourmaline or pink tourmaline, which are sometimes used to describe the fancy variety of this versatile gem.



Because the Opal has the colors of others gems, the Romans thought it was the most

precious and powerful of all. The Bedouins believed that Opals contained lightning and fell from the sky during thunderstorms.

Europeans have long considered the Opal a symbol of hope, purity and truth. Australian Aboriginal legend tells how the Creator came down from the heavens on a rainbow and delivered a message of peace for all mankind.

For ages people have believed in the healing power of the opal. It is reported to be able to solve depression and to help its wearer find true and real love. It is said to stimulate originality and creativity. Because the opal is porous, it is quite absorbent. So, due to its ability to absorb, it is thought that the opal can pick up the thoughts and feeling of people and amplify emotions.


It is said to be a powerful detoxification stones that invites positive energy. In traditional Hindu belief systems, the tourmaline is thought to help balance the energies of the body. Tourmaline is thought to affect different chakras depending on its color.

Red is related to the Muladhara, or the base chakra. Associated with sexuality, grounding and survival. Orange is linked to the Swadhisthana, or sacral chakra, governing relationships, enthusiasm and creativity. Yellow corresponds to the Manipura, the third