Uranium Milk Glass Phospherene Lead 
Answer: Uranium
Many vintage marbles have a curious property that delights kids and adults alike: if you shine a black light (or other concentrated UV source) on them, they fluoresce an absolutely brilliant green color.
Why do some vintage marbles shine brilliantly and some simply react to the presence of the black light like any other glass? The secret is the composition of the glass: many vintage marbles were manufactured with uranium infused glass. When illuminated by concentrated UV, the glass shines an intense (and stereotypically “radioactive”) green.
But why would anyone add uranium, however trace the amount, to glass marbles? Especially when you consider that back in the 1920s nobody was walking around with a pocket black light to make their marbles glow. Uranium infused glass, commonly called “Vaseline glass” by collectors because of its slightly cloudy appearance, takes on a special appearance when exposed to even the smaller concentration of ultraviolet light rained down upon us by the sun. Uranium infused glass vases, bowls, and prisms, and glass door panels took on a beautiful almost opalescent emerald quality when sunlight hit them just right.
Uranium glass use fell out of favor during the late 1930s and 1940s as the United States government snapped up all available Uranium for nuclear research, development, and weapons construction purposes. Today, a small handful of marble companies still make small runs of marbles with uranium glass and an even smaller number of glass artisans still craft vases, bowls, and decorative objects with the curious glass.
When you open an Office 2013 program, a start screen automatically displays showing you the various templates available and a list of recent documents opened in the left column. If you find this screen annoying and would rather pass it by, it’s easy to disable.
Domain users are not allowed to sign in with a Pin by default. However, using a little bit of GPO, we can change that.
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Not only is Adobe Photoshop a powerful hands-on image editing tool, it’s a very powerful hands-off image editing tool. Read on as we show you how to automate repetitive and routine tasks so you can spend your time more creatively, rather than cropping, correcting, and otherwise clicking.
If you’ve heard one thing about Windows 8.1, you’ve probably heard Microsoft is bringing back the Start button. Windows 8.1 includes many features that should have been included with Windows 8, and it can feel much less awkward on a desktop PC.
One of the biggest changes in Windows 8.1 is SkyDrive integration. In Windows 8, SkyDrive was available as a Modern app and a desktop app that you could install. In Windows 8.1, SkyDrive is integrated at the system level.
There may be times you want to remove a row or column from a spreadsheet, but you don’t want to permanently delete it from the worksheet file. Excel has a feature that allows you to temporarily hide a row or column from view.
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Alright, so almost everybody will either know how to do this already, or should be able to figure it out very quickly. For the rest, here is a very quick tip that will help you get your Google Calendar showing up in the OS X Calendar app.
