A Dozen (or more) Objects that Fluoresce Under a Black Light

Many materials glow or fluoresce when illuminated with black light. A black light bulb or black light emitting diode (LED) shines with high energy ultraviolet light. The human eye cannot perceive the light in this part of the light spectrum, therefore, the name “black” was given to this type of light.

Some substances have the property of being fluorescent, meaning they absorb ultraviolet light and re-emit the light almost immediately. The light emitted from those materials has a longer wavelength than the light absorbed because some of the original light’s energy is dissipated in the process. The longer wavelength light becomes visible and the material appears to glow. Fluorescent molecules have a more rigid structures and delocalized electrons.

Make Tonic Water Glow with Black Light

Quinine is the substance in tonic water that gives the bitter flavor. It also happens to glow a gorgeous blue under black light. Oddly, diet tonic water glows just as brightly. Some brands of tonic water glow more than others, so feel free to test them out in the store with a keychain black light.

Vitamins are Supposed to Make your Skin Glow: Who Knew Vitamins themselves Glow?

Vitamin A and the B vitamins thiamine, niacin, and riboflavin are strongly fluorescent. Try crushing a vitamin B-12 tablet and dissolving it in vinegar. The solution will glow bright yellow under a black light.

The following vitamins are quite fluorescent:

  • Vitamin A
  • Vitamin B
  • Thimaine
  • Niacin
  • Riboflavin

A B-12 tablet, crushed and dissolved in vinegar will light up bright yellow under black light.

Black Light makes Chlorophyll Glow Red

As we all remember from basic botany, it is chlorophyll that makes plants have a green color. But many people don’t know that chlorophyll lights up bright blood red under black light. For example, if you were to grind spinach leaves and mix with alcohol and filter through a coffee filter then the chlorophyll that stays in the filter can be illuminated with a bright red glow if a black light is applied.

Black Lights Cause Scorpions to Glow

Several scorpion species glow from ultraviolet light. Emperor scorpions, bark scorpions and yellow-tailed scorpions are some of the species that glow from ultraviolet light, but you would never know if from their normally subdued colors.

Human Black Light Stripes

 Blaschko’s Lines are stripes that are visible on humans under ultraviolet light. They don’t really, glow, but just become visible.

Black Lights Illuminate Many Dental Preparations

There are compounds in tooth whiteners, toothpaste, and some enamels that will glow blue under a black light. This is to prevent the teeth from having a yellow appearance.

Antifreeze Glows Under Black Light Illumination

Fluorescent material is added to antifreeze so that black lights can be used by investigators to find splashes when reconstructing car accidents.

Certain Gems and Minerals are Fluorescent Under Black Light

Fluorite, calcite, gypsum, ruby, talc, opal, agate, quartz, and amber are examples of Fluorescent rocks. Many gemstones and minerals fluoresce because of the impurities they possess.

Urine and Other Bodily Fluids are Fluorescent Under Black Light

Blood, urine and semen can be found using ultraviolet light. Often, crime scene investigators use black lights to detect these fluids to use as evidence. These bodily fluids contain fluorescent molecules, but blood does not. However, blood reacts with a chemical that can be detected under black light.

Money Glows in Black Light

Bank notes, especially high-value bills, often glow under ultraviolet light. For example, modern US $20 bills contain a security strip near one edge that glows bright green under a black light

Money, or more specifically, bills or bank notes sometimes glow when ultraviolet light is applied. This security precaution protects higher value bills and makes them more difficult to counterfeit. For example, US twenty dollar bills have a glowing strip near on of the edges.

Some Cleaners and Laundry Detergent Glow from UV Black Light

Your clothes actually become a bit fluorescent from some of the whiteners in laundry detergent. Residues from the whiteners on white material remain even after being rinsed and glow bluish white under black light. Other additives in laundry detergent also contain fluorescent dyes. These chemicals can even make white clothing show up as blue in photos.

Black Light Fluoresces the Spots on Bananas

The spots on ripe bananas will glow when black light is applied.

Many Plastics Fluoresce under Black Light

Neon colored acrylic often has fluorescent molecules, so it can be easy to tell if a plastic will glow under black light, just by observing it. Some plastic glows under black light without giving any visual indication when viewed under full spectrum light.