List Of Things That Glow Under Black Light - Science Notes

A black light reveals a hidden world of glowing objects by emitting ultraviolet (UV) radiation, which is mostly invisible to the human eye. Under this light, certain substances glow in brilliant colors, even if they look ordinary under daylight. This glowing effect, called fluorescence or phosphorescence, finds use in forensics, art, science, and everyday fun.

This guide lists common and surprising things that glow under black light, explains the science behind the glow, and explores how the type of black light affects what you see.

Key Takeaways: Things That Glow Under Black Light

• Black lights emit UV radiation, which excites certain molecules so they emit visible light.
• Fluorescent materials glow instantly under UV and stop when the light is off, while phosphorescent materials glow for longer.
• Many common objects glow, including vitamins, cleaners, minerals, body fluids, animals, and plants.
• Not all black lights are equal. Some emit more visible light or different UV wavelengths, affecting how well items glow.
• The glow color depends on the chemical makeup of the substance and the wavelength of UV light used.

What Is a Black Light?

A black light is a type of light bulb that emits mostly ultraviolet radiation. Although most bulbs also give off a faint violet glow, the majority of the light is outside the visible range. This energetic radiation excites molecules, often producing fluorescence or phosphorescence. A visible photon is released when a molecule loses the absorbed energy, making the substance appear to glow in the dark.

List of Things That Glow Under a Black Light

A wide range of both natural and synthetic materials glow under a black light:

• Tonic water (quinine) – glows blue
• Hennessy V.S Limited Edition cognac bottle – bottle glows bright green (liquor does not glow)
• Some vitamins and drugs – B12 glows bright yellow
• Chlorophyll – glows red
• Flying squirrels – bright bubblegum pink (fluorescence is extremely rare in mammals)
• Puffin beaks – bright blue
• Chameleon bones – bright blue, visible through living skin
• Scorpions – glow blue or green
• Glow in the dark paint
• People
• Teeth – usually glow white under black light
• Antifreeze
• Fluorescent minerals – glow various colors
• Many gemstones – including rubies
• About 1/4 of diamonds – glow various colors under black light
• Some body fluids – Saliva, sweat, urine, vaginal fluids, and semen glow, while blood does not
• Fluorescent dyes
• Bank notes – green strips in US currency
• Laundry detergent – glow blue
• Irish Spring soap – green
• Mr. Clean liquid cleaner
• Banana spots

• Some toys
• Most types of fishing line
• Some plastics
• White paper – white or blue-white
• Passports
• Some cosmetics
• Some animals, plants, and fungi (especially marine life) – usually green or blue
• Petroleum jelly (e.g.,Vaseline) – glows blue
• Uranium glass or vaseline glass – glow green, yellow, or blue
• Rock salt
• Fungus that causes Athlete’s Foot – glows orange
• Turmeric (a spice)
• Olive oil
• Canola oil
• Some flowers
• Certain postage stamps
• Highlighter pens – variety of colors
• Honey
• Ketchup
• Cotton balls
• Pipe cleaners – usually glow blue-white, although fluorescent ones can glow other colors

More Things That Glow Under Black Light

Have you found other surprising things that glow under a black light? Let us know in the comments or on social media!

Why Things Glow Under Black Light

The glow you see under black light comes from a process called fluorescence, where certain substances absorb high-energy ultraviolet light and release lower-energy visible light. Here’s how it works:

1. UV photons from the black light strike a molecule.
2. The molecule absorbs this energy and enters an excited state.
3. The molecule quickly loses some of this energy and returns to its normal state by emitting a visible photon, which is the glow you see.

This glowing effect is immediate and disappears as soon as the black light is turned off. Some materials also exhibit phosphorescence, where they hold the energy longer and glow even after the light source is removed. The exact color of the glow depends on the structure of the molecule and how it releases energy.

Not all materials fluoresce under black light. The presence of specific fluorophores (molecules that fluoresce) or chemical additives is what makes some items glow.

Why the Type of Black Light Matters

Not all black lights work equally well for making things glow. That’s because there are different types of black light sources, and their ability to produce fluorescence depends on the intensity and wavelength of ultraviolet light they emit.

Common Types of Black Lights:

• Fluorescent black light bulbs (BLB): Emit a narrow band of long-wave UV-A (around 365–370 nm) and very little visible light. These are best for seeing subtle glows.
• LED black lights: Energy-efficient and widely available, but the quality varies. Some emit a broader wavelength range or more visible light, which can wash out weaker fluorescence.
• Incandescent black lights: Less effective, since they produce more heat and less UV radiation.
• UV lasers and short-wave UV lamps: Can reveal different fluorescent features, but may also damage materials or skin.

Why It Matters:

• Shorter wavelengths (~365 nm) excite more substances and produce brighter fluorescence.
• More visible light output (like in many cheap LEDs) reduces contrast and makes the glow harder to see.
• Some items only fluoresce under specific UV wavelengths, so they may glow under one black light but not another.

To get the best results, choose a high-quality UV-A black light with minimal visible output. UV-A light is dangerous, so opt for a fluorescent black light bulb over a laser or short-wave UV lamp and avoid prolonged skin exposure or looking into the light.

Gallery of Things Glowing Under Black Light

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