Re: fluorscening minerals
You do not need a more expensive light, as there are minerals that you can buy for relatively modest sums (or find, for free) that will glow all of the colors of the rainbow (although very rarely in the same mineral specimen). Many of the multi-colored fluorescents come from Franklin, NJ, and most of these require a short wave lamp to in order to see their fluorescence. But you can still find individual minerals in blue, green red, etc. If you'd like a list of this e-mail me and I'll be happy to provide you with the information.
The light that you are using is undoubtedly a long-wave lamp. You can buy the same type of lamp for under $20 at any Home Depot. A short wave lamp will cost at least ten times that price and is also much more dangerous. Short wave ultraviolet radiation can cause skin cancer and even blindness if the eyes are not properly shielding and too much exposure occurs.
A few other caveats: one of the threads in this discussion stated that you should try to get some autunite and that uranium minerals (of which autunite is one) usually fluoresce. The later statement is not true. While autunite is highly fluorescent (bright green - even under long wave), primary uranium ores, like uraninite or pitchblende, and many secondary uranium deposits containing minerals like torbernite or carnotite, do not fluoresce at all. I'd also recommend that you do not include minerals like autunite in your son's collection. Inhalation or ingestion of small amounts of this mineral pose a significant health threat from the radioactive emanations (mostly alpha particles, which can do a lot of damage in lung tissue, and some gamma radiation as well. I keep all of my radioactive minerals away from my family in lead shielded boxes and in a well ventillated garage to remove traces of radon, which is constantly being produced as the uranium decays - first to thorium, then radium and then radon.
When your son is older and more experienced you may even want to invest in a more sophisticated uv lamp that has three ranges - long, short and midwave (such lamps cost about $400-$500). Short wave minerals are the most beautiful, but there are many minerals that only fluoresce under midwave uv, and others that are better under long wave than under shortwave like wernerite (meionite). Also some minerals will give you a different response under long an short waves, like the calcite from Coahuila, Mexico, which is pink under longwave and blue under shortwave uv. Also, you'll see great phosphorescence - an afterglow that will last several minutes after you turn the lamp off.
Have fun with your lamp. Let your son look at all of the other thigs in your house that are fluorescent as well - many shampoos, clothing dyes, even the anticounterfeiting strip on your ten and twenty dollar bills. Enjoy!
From Dr. Art Friedman - July 04, 2008 at 11:54:50