There are many naturally occurring blue things found in nature. While blue is less common than other colors like green and brown, there are still a number of interesting examples of blue in the natural world. In this article, we will explore some of the most notable naturally blue plants, animals, minerals, and other natural formations. Understanding the science behind natural blues gives us insight into pigments, light, evolution and more.
Blue Animals
Here are some of the most vibrant blue animals found in nature:
| Animal | Description |
| Blue morpho butterfly | This butterfly from Central and South America has brilliant blue wings that reflect light. The blue comes from the microscopic scales on the wings. |
| Blue tang fish | This bright electric blue fish lives in Indo-Pacific coral reefs. Their color comes from pigment cells under translucent scales. |
| Blue dragon sea slug | Also known as glaucus atlanticus, this small blue sea slug floats upside down on the ocean surface. |
| Blue bird-of-paradise | The males of this tropical forest bird have deep blue feathers on their heads, cheeks, throat, wings, and tail. |
| Blue jay | This common North American songbird has brilliant blue feathers on its back and head. |
The blue and violet colors in these animals primarily come from structural colors instead of pigments. Microscopic structures in feathers, scales, and skin refract and scatter light to produce blues without using any blue pigment. Iridescence from structural colors causes some animals to shimmer or change color when viewed from different angles.
Blue Plants
Plants have evolved many shades of blue flowers and foliage. Here are some examples:
| Plant | Description |
| Blue oak trees | These oak trees native to California have bluish-gray foliage. |
| Hydrangea | The popular garden shrub hydrangea produces blue, purple, and pink blossoms depending on soil pH. |
| Cornflower | This wildflower has vivid blue blossoms. Extracts were once used for blue fabric dye. |
| Glory lily | This South African plant has electric blue flowers with six petals. |
| Blue spruce | A type of pine tree with sharp blue-green needles native to western North America. |
The blue pigments in plants are primarily anthocyanin pigments. These water-soluble pigments reflect blue light. They appear blue under acidic conditions and change to red under alkaline conditions.
Blue Minerals
While less common than other colors, some naturally occurring minerals and gems exhibit blue hues. A few examples include:
| Mineral | Description |
| Azurite | A vivid blue copper carbonate mineral. |
| Blue calcite | A varietal of the calcium carbonate mineral calcite that ranges from sky blue to deep blue. |
| Blue quartz | Less common than colorless quartz, blue quartz ranges from pale to dark blue. |
| Sodalite | A cubic mineral that can exhibit blue to blue-violet coloration. |
| Blue lace agate | A banded agate stone displaying delicate bands of light blue. |
The blue and violet hues in these minerals originate from trace elements present during formation. Elements like copper, iron, and sulfur combine to provide vibrant blue minerals.
Other Blue Natural Phenomena
Beyond specific organisms and materials, there are some other notable blue phenomena that occur naturally:
| Phenomenon | Description |
| Blue lava | Molten lava that appears bright blue due to high sulfur content. |
| Blue ice | Dense ice that takes on an intense blue color due to minimal air bubbles and impurities. |
| Blue fluorescent rocks | Some minerals glow blue under ultraviolet light due to fluorescence. |
| Blue caves | Cave formations in places like the Bahamas exhibit blue color from water clarity. |
| Blue Pond of Hokkaido | A vivid blue pond in Japan colored by minerals in the water. |
These phenomena demonstrate more ways that water, minerals, physics, and chemistry can produce striking blue colors in nature.
Conclusion
While less prevalent than greens and browns, blues do commonly occur in the natural world. Animals, plants, minerals, and other phenomena exhibit a wide spectrum of blues produced through pigments, structural colors, and the physics of light and color. Studying the blues found in nature continues to reveal new insights into biology, geology, optics, and more. The examples here showcase some of the most vibrant and interesting examples of things that are naturally blue.
