9 LED Mini Aluminum UV Ultra Violet Black Light
Size: 8cm x 2.3cm
Requires 3 x AAA Alkaline batteries not included.
Some rock minerals have special characteristics that allow them to glow fluorescent under UV light. Some minerals glow only under longwave UV light, like that produced by commercially available black lights. Others glow under shortwave UV light. Shortwave UV rays are damaging to the skin and can cause sunburn, so these bulbs are not commercially available. Even though a rock is known to fluoresce, that does not mean every specimen will glow when exposed to UV light. The ability to glow depends on the presence or certain organic minerals from the earth that make up the rock.
Scheelite
A popular, collectible mineral, scheelite (calcium tungstate), glows blue under short wave ultraviolet light.
Flourite
Flourite (calcium fluoride) usually fluoresces blue, but many specimens emit various colours, including yellow, red, white, green and red. A few specimens simultaneously produce different colours when viewed under long wave and short wave UV light, while a number of fluorite specimens’ phosphorescence (glow without a visible light source) in a third colour.
Commonly found in short to long crystals, scapolite, which means “shaft” in Greek, emits orange or yellow colour and, on rare occasions, red under black light. As an attractive gemstone, scapolite's colours vary from yellow or orange to pink or violet.
Willemite
Nearly all willemite ore (zinc silicate) glows bright green under black light and a few will phosphorescence. This rare mineral, a source of zinc ore, is one of the finest specimens of fluorescent material.
Calcite
Not all calcite minerals are florescent, although some specimens glow red, yellow, pink or blue under UV light. Calcite (calcium carbonite) gets its name from the Greek "chalix" (lime) and has many uses, such as cement, mortars, or as an ornamental stone.
Autunite
One of the most beautiful radioactive minerals, the yellow-green colour of the autunite mineral (hydrated calcium uranyl phosphate) fluoresces under ultraviolet light. Strangely, when autunite loses water it irreversibly converts to an entirely different substance called meta-autunite-I. After many years, the meta-autunite turns to powder, ruining the specimen.
Hyalite
One of many names for the common opal, hyalite is a colourless to sky-blue transparent colour that fluoresces green under UV light.
Gypsum
A common sedimentary mineral, gypsum, (hydrated calcium sulfate) glows blue under ultraviolet light. As a natural insulator, gypsum feels warm to the touch, and is commonly used in drywall.
Eucryptite
Some eucryptite (lithium aluminum silicate) minerals fluoresce pink under ultraviolet light. Eucryptite crystals, although transparent to translucent, are rarely cut as gemstones.