A diamond's color comes from impurities, defects, and unique formation processes

A 37.41 carat, bicolor diamond likely formed from two distinct geological processes

Discovered in a Botswana mine, half the stone is clear, having formed from carbon being squeezed under extreme heat and pressure into a tight crystal structure. The pink half formed earlier and resulted from minor bending of the crystal during tectonic activity without causing it to brown or break.

Diamonds have been made from substances such as peanut butter and carbon dioxide, though they can be created from any carbon-rich material under extreme pressure and temperature.

Some synthetic diamonds are purposely made with defects for new technologies

Grown in plasma-filled chambers or reactors where pressures reach 800,000 pounds per square inch, diamonds can develop properties like electrical conductivity and magnetic field sensitivity through exposure to elemental impurities or removal of some of their carbon atoms.

How diamonds form in the deep earth

Deep within Earth's mantle, diamonds form from carbon-bearing fluids. The formation of these beautiful gemstones, the only direct samples we have of the mantle, helps scientists uncover how carbon functions deep inside our planet. Understanding this complex process aids in the exploration for new diamond deposits.

The new phenomenon of 15-minute lab-grown diamonds

In 2024, scientists developed a groundbreaking method to create diamonds at normal room temperature and pressure. This efficient and simple process contrasts with the traditional high-pressure, high-temperature method. While limitations still exist, such as minuscule sizes, this discovery moves us toward an exciting new era in diamond synthesis. Check out the article for further information about how diamonds are made.

Several birthstones play key roles across modern technologies

Diamonds are used in drills and quantum computing, while peridot and zircon help in steelmaking and carbon capture. Rubies, sapphires, and alexandrite enable several varieties of lasers found in medicine and advanced optics. Garnets are found in water filtration systems and radiation detectors. Sapphires are used as substrates in semiconductors.

Diamond rain is thought to form within Uranus and Neptune, whose interiors can compress carbon atoms from methane into these falling crystals.

As crystals form, their properties and the shapes they take on, including cubic, tetragonal, and hexagonal patterns, reflect the arrangement of their constituent atoms.

Chromium contaminants in a ruby crystal gave the world's first laser its red color

The red light originates from a long-lasting excited electron state in the element's atomic structure. The brittle gray metal has historically been used in pigment production, the manufacturing of rust-resistant stainless steel, and the creation of durable coatings with long-lasting shine for metals, wood, and leather.

Water is naturally tinted with a slight blue, but sediments and organics can alter its color

The innate coloration comes from water absorbing red light in the visible spectrum more than green or blue, giving shallow waters in some parts of the Caribbean their turquoise hue. If sand is light, it can be churned up by turbulent water, clouding its appearance. Plankton and other organisms can color water by affecting how the rest of the spectrum is absorbed or reflected.

The outermost shell of electrons in an atom dictates how it bonds to other atoms, including those of the same element, and the properties of the materials composed of those atoms.

Atmospheric composition and temperature impact the color of lightning

Just as fire ranges from red to blue with increasing temperature, lightning's blueish-white comes from the superheating of air. The emission of light from the predominantly nitrogen- and oxygen-rich atmosphere produces a purple tint, with additional color caused by light scattering from humidity, hail, dust, and ash.

A startup is trying to create the diamond equivalent of the gold standard

It's called the Diamond Standard Co, and it uses an algorithm to assign standard values to a variety off small diamonds, grouping them together into individual coins. Historically, diamonds haven't been able to be classified as commodities or standardized like gold because they aren't uniform—factors such as clarity, cut, color, and carat size significantly influence the value of a diamond.

What is the rarest color in nature?

Plants, animals, or minerals found in nature bear almost every color imaginable. There are two factors that influence what hues you see in the wild: physics and evolution. So, which colors are you least likely to see in the natural world? Victoria Hwang explores one of nature's rarest spectacles.

Although they rely on radioactive elements to operate, everyday technologies such as electronic exit signs, some wristwatches, and smoke detectors are not dangerous, unless they are damaged and their radioactive material is inhaled or swallowed.

Rocks, crystals, and gemstones are all made of minerals—solids that form from natural processes, such as evaporated water leaving salt behind or lava rapidly cooling into a solid.

Solar activity and the density and chemical composition of the air affect auroral colors

Oxygen atoms can emit red and green light when energized by collisions with the solar wind, but red takes longer to be emitted and is disrupted by bumping into other molecules. This causes red light to appear at higher altitudes, where the air is less dense. Higher-energy solar wind can penetrate to lower altitudes and collide with more abundant ionized nitrogen, which produces blue light.

Synthetic diamonds may be used to cool microchips

The strong carbon bonds in diamonds efficiently carry vibrations, allowing them to conduct heat several times faster than copper, a metal commonly used in heat sinks. AI and high-performance computing have pushed researchers to investigate alternative materials for cooling solutions.

The different energy levels of each element result in unique colors when burned

When heated, electrons absorb energy and move to excited states within an atom. They promptly drop back down and release light energy corresponding to the size of the drop, which is unique to each element.

Diamond engagement rings were popularized via an ad campaign

In 1947, an ad agency copywriter wrote the De Beers diamond company's slogan, "a diamond is forever"—and diamond engagement rings became basically required for brides-to-be. This video tells the story of exactly how the ad campaign happened, and why it was so impactful.

Where does your glass come from?

Glass is created from silica sand, soda ash, and limestone. The more transparent you want your glass to be, the higher the purity you need from your silica—a rarity. Colorless, low-iron glass featured in skyscraper windows and Apple's cube-shaped showrooms has increased demand for such pure silica.

By separating light with tools such as prisms, scientists can reveal the presence and composition of celestial matter by identifying color fingerprints unique to specific elements and molecules.

Geode formation begins with trapped gas bubbles in igneous or sedimentary rock

Over thousands or millions of years, water seeps into the cavity created by the bubble and deposits minerals, which slowly build and crystallize into quartz, agate, amethyst or other crystals.

The medieval meaning of your birthstone

Medieval people viewed birthstones very differently from modern jewelry marketing. Rather than simply being decorative, gems were believed to possess extraordinary magical, medical, and mystical powers. This article breaks down some fascinating insights into medieval gemstone beliefs, including that diamonds could fend off insanity and nightmares.

Wedding rings can be traced back to ancient Egypt, where the ring symbolized eternity

The tradition later spread through Greece and Rome, evolving with precious gems during the medieval period. Diamonds became central after De Beers' 1947 "a diamond is forever" campaign, boosting sales by 50% in three years.

Breaking down sunlight and why the sun appears yellow despite emitting green light the most

This peak intensity is produced alongside a spectrum of other colors, which, when combined, make the sun appear white in space. Since Earth's atmosphere scatters bluer and greener wavelengths of light more than red and orange wavelengths, sunlight reaching Earth's surface appears yellow, while the sky appears blue. (Some readers may experience a paywall.)

Starting with red, colorful objects will appear to lose their colors the deeper they are submerged because water scatters light, reducing the amount available to reflect off objects and be observed.

Color originates from the brain processing light of varying wavelengths

Various geometric models, including Newton's color circle of hue and saturation and the horseshoe-shaped XYZ space for mixing colors via vector mathematics, have been proposed to describe colors accurately. However, these models do not encapsulate the variety of psychological effects that cause perceived colors to differ from mathematical representations.

View an animation of how certain chemicals fluoresce—that is, emit visible light after having absorbed higher-energy light, such as ultraviolet radiation.

Fireworks' chemical composition and internal layout produce their unique displays

The burning of different metal compounds, facilitated by combining fuel with oxidizers, results in explosions of varying colors. The timing and pattern are engineered through the arrangement of pellets and fuses.

Bright blue fireworks are the most difficult color to create

Copper chloride emits blue light when heated, but breaks down at the temperatures created when fireworks explode. Pyrotechnicians continue to search for an ideal mixture that provides a temperature high enough for copper chloride to shine brightly without being destroyed.

Blacklights can illuminate certain biological materials, including blood, teeth, and fingernails, because they contain fluorophores—molecules that visibly glow immediately after exposure to higher-energy light.

A nuclear reactor's characteristic blue light is produced from superluminal particles

When light travels through water, its effective speed is 25% lower than its speed in a vacuum. Just as sound waves bunch up and produce a sonic boom when objects move faster than the speed of sound, particles moving faster than this reduced speed generate a shock wave of light, visible as a blue hue.

Fireworks make a loud booming sound after explosion due to air expanding faster than the speed of sound.

From the surface, Mars can appear butterscotch, golden brown, and even green

Images from orbiters, landers, and rovers show that Mars has a mix of surface colors resulting from variations in the mineral compositions of different regions. The reddish tint when viewed from Earth comes from kicked up particles of rusted iron.

Cerulean eruptions result from sulfur being heated by molten rock

During eruptions, warm-colored lava at temperatures between 700 and 1,200 degrees Celsius (1,300 and 2,200 degrees Fahrenheit) burns minerals as they escape from underground reservoirs. In some volcanoes, such as Indonesia's Kawah Ijen and Ethiopia's Danakil Depression, abundant sulfur compounds that burn with blue flames appear to change the color of the melted rock.

High solar activity can produce pink and purple auroras

Although less common, energetic enough charged particles from the sun that descend to an altitude of about 100 kilometers (62 miles) can strike a mixture of ionized and neutral nitrogen molecules, causing them to emit red and blue light, which our eyes perceive as purple.

The conditions needed for cloud iridescence, or rainbow clouds

The relatively rare phenomenon occurs when sunlight scatters off tiny water droplets or ice crystals in thin, newly-forming or semi-transparent clouds, such as altocumulus, cirrocumulus, lenticular, and cirrus varieties. This effect is similar to what is seen in soap bubbles and mother-of-pearl shells and produces pastel-like colors.

Ernest Rutherford's gold foil and nitrogen experiments revealed nuclear structure

Observing high-angle deflections when alpha particles were fired at gold foil led to an atomic model with a dense, positively charged nucleus. Firing those particles at nitrogen resulted in the emission of hydrogen nuclei—protons—leading to the discovery of the subatomic particle.

Blood color differs across the animal kingdom, with some animals producing blood that appears green (a group of lizards in New Guinea) or blue (horseshoe crabs).

While most cells possess DNA, red blood cells destroy their nuclei to maximize the amount of oxygen they carry and more easily alter their shape to fit through narrow blood capillaries.

DNA may serve as a flame retardant by self-extinguishing some burning materials

When DNA burns, phosphate groups release phosphoric acid, and nitrogenous bases release ammonia. These molecules, along with the sugar in DNA's backbone, shift the combustion reaction toward the formation of intumescent char. This puffy, carbon-rich layer protects open flames from burning the material beneath.

The strong nuclear force, which keeps atomic nuclei intact, is mediated by gluons—massless particles that bind together the quarks that make up protons and neutrons.

Why your favorite color is probably blue

From a young age, we are primed to choose a favorite color, but strangely as we grow up, our preference often changes—and it’s largely due to influences outside our control.

As of 2026, the rarest mineral on Earth may be kyawthuite, an orange gemstone whose only known specimen was found in Myanmar in 2010.

Distinguishing between natural and artificial, or induced, radioactivity

Naturally occurring radioactivity comes from radioactive elements underground, cosmic radiation from the sun and other objects in space, and radioactive atoms that make up the molecules we breathe, eat, and drink. Artificial radioactivity is predominantly generated for medical applications and industrial activities.

See how fireworks are made and which metals are responsible for different colors.

During the fall, shorter days trigger cells in leaves to produce less chlorophyll, a green pigment that is typically present in sufficient concentrations to mask other pigments, such as yellow and orange.

More than 90% of the atoms in the human body were forged by stars, with almost three-quarters originating from the explosion of massive stars.

Shooting stars are streaks of light produced by meteoroids

As these rocks enter Earth's atmosphere at high speeds, friction causes them to burn up, briefly leaving streaks of light. The color of these fireballs can be used to determine the composition of the meteoroid, if it does not reach the ground and become a meteorite for analysis.