Harry Pristis
Bronze Member
Many fossils (from the Badlands, Aurora, Bone Valley, etc.) will flouresce under ultra-violet light. Here's one that I photographed using normal and UVA light.
Anyone Here with UVA Flourescent Shark Teeth?
- Thread starter Harry Pristis
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centfladigger
Hero Member
cool, now I have to go through all my junk and the kids to find the light,lol I`ll check ,my teeth from the mines
LanceHall
Jr. Member
I've tried my collection with a store bought flourescant "black light" but no luck. Are there different types of "black light"??
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Harry Pristis
Bronze Member
- Thread starter
- #4
LanceHall said:
"Black light" and "UVA" are equivalent, pretty much, according to Wikipedia:
A black light, or Wood's light, is a lamp that emits long wave UV radiation and very little visible light. Commonly these are referred to as simply a "UV light". Fluorescent black lights are typically made in the same fashion as normal fluorescent lights except that only one phosphor is used and the normally clear glass envelope of the bulb may be replaced by a deep-bluish-purple glass called Wood's glass, a nickel-oxide–doped glass, which blocks almost all visible light above 400 nanometers. The color of such lamps is often referred to in the trade as "blacklight blue" or "BLB." This is to distinguish these lamps from "bug zapper" blacklight ("BL") lamps that don't have the blue Wood's glass. The phosphor typically used for a near 368 to 371 nanometer emission peak is either europium-doped strontium fluoroborate (SrB4O7F:Eu2+) or europium-doped strontium borate (SrB4O7:Eu2+) while the phosphor used to produce a peak around 350 to 353 nanometers is lead-doped barium silicate (BaSi2O5:Pb+). "Blacklight Blue" lamps peak at 365 nm.
While "black lights" do produce light in the UV range, their spectrum is confined to the longwave UVA region. Unlike UVB and UVC, which are responsible for the direct DNA damage that leads to skin cancer, black light is limited to lower energy, longer waves and does not cause sunburn. However, UVA is capable of causing damage to collagen fibers and destroying vitamin A in skin.
The UVA produced by the light-emitting diodes in my flashlight is at a frequency of 395 nm. This is the new technology that doesn't use a tiny flourescent blue-glass tube. Instead, it uses 51 LEDs that look like . . . well . . . like most other LEDs in a flashlight.
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