What are Pigments?
When we see the vibrant hues in our environment, it’s mainly thanks to pigments. These are compounds that absorb certain wavelengths of light and reflect others. So when our eyes perceive color, what they’re really seeing is the light that’s been reflected off pigments.
The exact color of light a pigment absorbs or reflects depends on its molecular structure. Some pigments, like those found in showy flowers, absorb most wavelengths of light and reflect only the colors we see. Others, like the pigments in certain metals, reflect nearly all light, giving them a shiny appearance.
Pigments aren’t just in the petals of a flower, the feathers of a bird, or the paints an artist uses. They’re in everything from our skin to the foods we eat. These pigments give carrots their orange color and tomatoes their red shade.
Match each Pigment with its Color.
Pigment 1: Red
The red pigment, named erythrosine in scientific terms, plays incredible roles on this stage of light. It is capable of absorbing green and blue light waves while reflecting the red ones. This is where the red color that catches our eye comes from.
But that’s not all! The wavelength of light absorbed and reflected is closely tied to its molecular structure. This 3-dimensional arrangement of atoms gives the red pigment its distinguishable bold and fiery hue. The red pigment paints our world in brilliant shades and is abundantly found in both nature and in human-made products.In nature, red pigments are generally derived from:
- Certain types of soil
- Plants such as roses and red seaweed
- Insects especially the cochineal bug
For industrially produced pigments, key sources include:
- Chemical reactions involving chemical compounds
- Minerals that are ground into a powder
Pigment 2: Yellow
Yellow, generally associated with energy, and vivacity, is not just a color, it’s a tribute to the power and intensity of light. Its presence manifests in an object when blue light is absorbed and red and green light are reflected.
- Plants: Marigolds, sunflowers, and safflower are just a few examples of rich sources of yellow pigments.
- Minerals: Ochre is a natural clay earth pigment found in a yellow form among others.
- Insects: The lappet moth caterpillar, when boiled, releases a rich yellow pigment that has been traditionally used in textile dyeing.
Pigment 3: Blue
Interestingly, blue pigment reflects blue light while absorbing other light waves. This results in an intense, pure blue color, particularly noticeable when the pigment is applied in paint.
One trait that makes blue pigment a crucial component in various products is its resistance to fading. It’s stable under various environmental conditions, including sunlight and heat, which enhances its longevity on numerous surfaces such as canvas, paper, or buildings. This stability is a result of the crystalline structures formed by particles of blue pigment.
Two famous natural sources of blue pigments are lapis lazuli and azurite. Lapis lazuli has been exploited for centuries for its vibrant blue hue, while azurite, a soft, deep-blue copper mineral, is also well known for its intensity.
Another well-known blue-colored mineral is cobalt, which is used in the production of a strong blue pigment known as cobalt blue. This pigment has been widely used in industries like ceramics and glass-making due to its brilliant color and resistance to fading.
Pigment 4: Green
Green pigment holds a significant place in our visual experiences. It’s soothing to look at and often symbolizes nature and tranquility. The stability and resistance to fading of green pigment are commendable, akin to red, yellow, and blue pigments.
Many minerals, for instance, naturally exhibit green hues. Malachite and brochantite are mineral-source examples.
Chemical reactions often produce robust green pigments as well. For instance, mixtures of blue and yellow pigments result in various shades of green.
Plants hold the most abundant source of green pigment, specifically chlorophyll. This pigment plays an essential role in photosynthesis, a process that sustains plant life and, by extension, all life on Earth.
Pigment 5: Orange
This pigment has a distinct hue that occupies a space halfway between the primary colors red and yellow. It’s a warm color known for its high visibility, making it a common choice for traffic signals and safety equipment.
A common source of orange pigment is the mineral Realgar. Found typically in low-temperature hydrothermal veins, it’s a toxic arsenic sulfide mineral that, despite its toxicity, has been used in firecrackers and as a pigment in paints for centuries.
Another common source of orange color is the Crocus Sativus flower, specifically its stigma, used to produce saffron.
A deeper understanding of pigments not only enriches our appreciation of color but also opens the door to further exploration.
