Basics about black lights.

[Backyard goldmine]

I quickly searched threads that mention black lights just to see what people have been saying when talking about them. I did a little reading up on them last week and found out there is more to it than just pointing a black light at a bottle and seeing if anything happens. So here is what I learned with pictures showing the differences in black lights.
1. Black lights come in different light wavelengths and they also come in incandescent or LED bulbs. LED bulbs are the only bulbs that can emit a specific wavelength. You’ll want an LED light. An article I read said the lower the wavelength number, the more things glow. I got a 365 nm wavelength and I’m happy with it so I didn’t buy any others.
2. It matters how you point the light at the bottle. If you’re checking for bright glows, like uranium or manganese, it doesn’t matter how you point the light at the bottle. It does matter when you look for minerals that do not glow as bright. When I used my incandescent bulb, I figured out quickly that if you hold the bottle so you’re looking at the base, then hold the light against the bottle and shine the incandescent bulb towards the top of the bottle, you’ll see the base glow. Then, when I used the LED bulb, that didn’t work. I had to hold the bottle where I was looking at the bottle and shine the LED bulb into the side of the bottle.
Also, the more visible light or daylight there is, the dimmer the glow will be.

In the pictures, all of the brighter pictures are from the LED 365 mm light.

 

[Backyard goldmine]

Here are some more pictures using my 365 flashlight

 

[Backyard goldmine]

A slight edit to my post. When trying to tell if you have uranium glass or manganese glass, the easiest way to tell is by using a 395 nm wavelength uv light. ONLY uranium glass will shine bright using 395 nm wavelength uv light. If you look at my pictures, I only have manganese glass. If any of it was uranium glass, it would have glowed just as bright using either of my uv lights.

 

[Sitcoms]

Super useful information, I honestly had no idea about the different wavelengths and how manganese will glow under the correct one. The dump I've been frequenting this summer has turned up a few pieces of uranium glass (mostly broken), so I purchased an UV flashlight last month - turns out I might be missing out on some manganese glass as it's a 395 nm wavelength one! Looks like I'll be buying a lower wavelength one soon too.

 

[naylor]

I have some bottles with heavy manganese content, and they glow just as brightly under 395 wavelength as they do 365. And I also have a few that glow faintly green under 395, but not at all under 365 for whatever reason. But in general, the 365 does seem to make most manganese bottles glow a bit more. And I've got lots of bottles that glow orange under 365, which do not glow at all under 395 ... I'm not 100% sure what element is causing the orange, since not every bottle exhibits that.

 

[Backyard goldmine]

I have some bottles with heavy manganese content, and they glow just as brightly under 395 wavelength as they do 365. And I also have a few that glow faintly green under 395, but not at all under 365 for whatever reason. But in general, the 365 does seem to make most manganese bottles glow a bit more. And I've got lots of bottles that glow orange under 365, which do not glow at all under 395 ... I'm not 100% sure what element is causing the orange, since not every bottle exhibits that.