Play-of-color: when nature paints
Play-of-color.
Whimsical, but very accurate!
Technically speaking, a gemstone is classified as a mineral that is beautiful, rare and durable.
Phenomenal gemstones are those jewels that go above and beyond with exceptional and stunning attributes.
While there are a number of phenomena that gemstones can have, one of the most well known and magical is play-of-color.
~Assorted opal pendants by Parle
Opals are famous because of these pinpricks and flashes of color. Play-of-color can appear like the board strokes of a paintbrush, little flecks of light, or a brilliant patchwork of bold colors.
These patterns are called flash fire, pin fire and harlequin, respectively.
Play-of-color is caused by an interaction of light with opal’s unique structure; unlike other gemstones, opals are amorphous.
They don’t have a uniform, repeating, stacked structure of atoms. Most gemstones always crystallize in the same structure, the atoms appearing the same way, in the same pattern, every time.
Amorphous gemstones do not.
Opals are comprised of microscopic spheres of ancient silica ‘gel’ that build on top of one another in irregular forms – not a very romantic sounding description given play-of-color’s enchanting appearance!
When light enters an opal, it has to squeeze through the microscopic gaps between each silica sphere. This action forces the light to slow down and bend, which in turn returns the light to our eyes as a stunning display of color flashes.
The colors, patterns and intensity of play-of-color that we see depend on the size and density of the silica spheres each opal is made of.
This means that truly, no two opals are the same.
~Different play-of-color patterns, photomicrographs by Isabelle Corvin
Play-of-color can easily look like an abstract painting, fireworks, or in some cases, a wild landscape photograph!
In certain stones with play-of-color, the same section of color may appear to change drastically to a different color when the light strikes the stone from a different angle. This is called directionality.
With unique patterns and colors, opals are a mesmerizing gemstone, and it’s no wonder that they have captivated people for generations.
Shakespeare even referenced it in Twelfth Night; “For thy mind is a very opal.”
Arab tradition claims that Opal was created where lightning struck the ground, and the play-of-color was caused by the trapped lightning flashing in the stone.
Certain patterns of play-of-color certainly evoke that imagery!
In the Middle Ages, opal was considered a very powerful gemstone. Sometimes called ‘the magician’s stone’, supposedly it would grant all the magic of the colors it displayed. Given that most opals showcase three or more colors at a time, this made it highly prized.
When you see the dance of colors inside an opal, you truly know why the phenomena was given the name it was. The colors are playing, always in motion, vibrant and loud.
Play-of-color is a wonderful addition to the already extensive, beautiful and unique catalog of gemstones. A reminder to us all to play a little each day.
~ Blog by Isabelle Corvin, Staff Gemologist and Merchandising Manager; this article was also featured by The American Gem Society on their blog https://www.americangemsociety.org/natures-artistry-opals-phenomenal-play-of-color/