Greetings Beaders, Leah here from Eureka Crystal Beads! I’m excited to bring you the 6th installment of 12: Birthstones! At the beginning of each month I’ll bring you a blog that is chock-full of everything you might want to know about that month’s stone. Were you born this month? If so, you might take particular interest in my sixth blog in this series: OPAL, the birthstone for October.


Opal is a hydrated amorphous form of silica. It’s water content can range from 3 to 21% (!!) by weight, but is usually between 6 and 10%. Because of its amorphous character, it is classified as a mineraloid, unlike crystalline forms of silica, which are classified as minerals. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock. Fun Fact: Opal is the national gemstone of Australia!

There are two broad classes of opal: precious and common. Precious opal displays play-of-color, common opal does not. Play-of-color is defined as “a pseudochromatic optical effect resulting in flashes of colored light from certain minerals, as they are turned in white light.” The internal structure of precious opal causes it to diffract light, resulting in play-of-color. Depending on the conditions in which it formed, opal may be transparent, translucent or opaque and the background color may be white, black or nearly any color of the visual spectrum. Black opal is considered to be the rarest, whereas white, gray and green are the most common. In addition, opal may exhibit adularescence, a form of iridescence.



A lovely way to appreciate Swarovski’s take on Opal is via their amazing selection of Rivolis! With beautiful backgrounds, finishes, and facets Swarovski is able to display the most lovely opalescent plays of color to more closely simulate the striking visual of an opal. Pictured here are just some of the (custom coated!!) 12mm Swarovski Crystal Rivolis we offer: White Opal Electra, White Opal Golden Sahara, White Opal Heavy Light Vitrail, White Opal Medium Vitrail, White Opal Volcano, and classic White Opal.


If you’re a believer in the metaphysical properties of stones, Opal is thought to encourage both freedom and independence. It is said to enhance cosmic consciousness and induce psychic and mystical visions. It stimulates originality and creativity, helps to release anger and claim self worth, aiding in accessing and expressing one’s true self.

Do you want to easily see everything “opal” that we have to offer? Take a peek at this “opal” search on our website! There are simply so many opalescent options to choose from (Rivolis, Chatons, Bicones, Seed Beads, oh my!) and they truly add a lovely quality to any project. My favorite time to use them is when I want to introduce some additional texture to a piece that will offer a different play on light as well!

And for those worrying: there’s is a long and varied history behind the superstition of opals being “bad luck.” Rest assured, as usual, there are good explanations for most everything when you look at both science and history… Take a look here to read more and breath easy. 🙂

Is your birthstone Opal? Do you have a special piece of opal jewelry that has a lovely story behind it? I’d love to hear – comment below! 🙂

Until next time, folks! Happy Beading!


4 Comments Add yours

  1. Georgianna Powers says:

    Hi Leah! Thank you very much for your informative article. I appreciate learning new things every day, and always wonder where my “nugget” of the day will take me. Today, it will take me to google, to find out more about the word adularescence, which I don’t remember seeing before. If I am lucky, google will have images that speak for the word, and delight my eyes while I learn. Thank you also, for showing the rivolis that have that opalescent quality….I could hear my budget squeaking at me! With an adventurous smile, G.

    1. So happy to have been of help, Georgianna! Truth be told, I had to look up adularescence as well when I was doing my research and, low and behold, it’s a quality in two of my favorite stones – Rainbow Moonstone and Labradorite! ❤ The more you know… 😉

  2. sue says:

    Hi Leah-Opal is my birthstone and my favorite piece of opal, actually pieces of opal, are contained in a jar. I was so fortunate in the late 70’s to visit my cousin in Australia and while I was there, met a couple of fellows who were digging at the Cooper Pedy (sp) opal mines. They gave me a handful of opal chips in a jar of water from their dig–a jar full of happy memories from my adventure.

    1. How awesome, Sue!! I’m sure they look amazing submerged in water! It truly helps the light to play off of them!

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