New Research Shows Rainbow Wrack Seaweed Has Iridescent Colors Just Like An Opal

The brown algae known as Cystoseira tamariscifolia has been found to impart colors similar to opals.

New research shows rainbow wrack seaweed has colors similar to opals.
Ian Waldie / Getty Images

The brown algae known as Cystoseira tamariscifolia has been found to impart colors similar to opals.

While algae may not normally be considered wildly attractive, the brown algae known as Cystoseira tamariscifolia, or rainbow wrack, has been found to contain the same nanostructures found in opals, which gives this seaweed a beautifully colorful and iridescent sheen.

This common algae is shockingly abundant along the coast of the Atlantic Ocean around Europe and also along the Mediterranean Sea, and while its hue is a simple olive color when pulled out of the water, when it is immersed deep beneath the ocean its colors are anything but ordinary, as ScienceAlert report.

New research conducted by Bristol’s School of Physics and Department of Electrical Engineering has shown that the gorgeous iridescence of rainbow wrack seaweed is derived from nanoscale spheres, which have the ability to regulate the amount of light that is reflecting from the cells of this seaweed.

So far, opals are the only other objects present in nature that have the same iridiescence as rainbow wrack seaweed, only, with opals, it is water deposition that creates the gorgeous colors out of silica, while this particular algae obtains its colors from an oil that the rainbow wrack creates rather than silica.

As the study’s lead author, Martin Lopez-Garcia, elaborated, the oils produced by this algae that help to create its vivid hues came as a big surprise to scientists.

“The formation of opals from oil droplets is a completely new discovery.”

Depending upon light conditions, rainbow wrack seaweed can go from an ordinary dark green to having vibrant, opal-like colors with the full sun shining upon it.

Ruth Oulton, a co-author of the new study, proclaimed that this is the first occasion where scientists have found an object similar to an opal that has been found inside a living organism, as Live Science report.

“It’s the first time that an opal’s been found that’s not made of hard material inside a living thing.”

According to Lopez-Garcia, the science behind this brown algae could have profound implications for the future of technology.

“If nanotechnologists were able to understand and mimic the dynamic properties of this seaweed opal, we may in the future have biodegradable, switchable display technology that may be used in packaging or very efficient, low cost solar cells.”

The new study on rainbow wrack seaweed producing its own iridescent opal colors can be read in full in Science Advances.