Normal aluminum like you find in the ground, not the man made stuff
ALL aluminum is man made. What exists in the ground is aluminum-oxide which is a white/grey granular material. The oxide is converted into the base metal by use of an electric arc furnace. (the power bill is huge) Aluminum as the metal you are familiar with in recyclable soda cans does NOT exist in nature. NO, aluminum is a metal, and like all other metals, only glows if heated to a high enough temperature to do so... You can recycle 100 cans for the cost of what it takes to make the aluminum for ONE NEW can.
If you heat it up hot enough, yes. Of course, any atomic matter will also behave that way.
An interesting thing about aluminum is that when you oxidize it, it actually becomes harder and more stable, but loses its metallic propery (it's what sapphire is made of in larger crystaline form). It's found this way in nature, as aluminum oxide in feldspars and most importantly bauxite. The melting point of alumina is extremely high, however. It's mixed with other chemicals where it dissolves instead, like gold in mercury. Then the pure aluminum is later extracted. It doesn't glow in the dark.
Not at visible wavelengths at room temperature.
As rowlfe said, aluminium does not exist free in nature. There are quite a number of minerals and compounds containing aluminum that are phosphorescent, though--there is a long list in the link below. The primary ore of aluminum is bauxite, but I don't think it is typically phosphorescent though it may be under certain circumstances. . Technically, aluminum is not man-made, so be careful using that term. All aluminum in existence is created in supernova explosions during star death. (This IS the Astronomy Space forum, after all.) All pure aluminum metal is *refined* by man, but the element itself isn't man-made. (There are some transuranic elements such as plutonium that do not exist in nature and have only been made by humans, so the point is relevant though perhaps not pertinent to your question. Aluminum isn't one of them, though.) . Edit: If you don't learn what you want here, you might consider reposting this question in the Geology section. That bunch probably knows more about minerals and such than the Astronomy Space crowd does.
