紫外线和荧光矿物质

紫外线和荧光矿物质

紫外线（UV）是波长比可见光短的光，范围从大约25nm（纳米）到400nm。尽管我们看不到紫外线，但是当可见光暗淡或不存在时，我们可以看到紫外线对荧光矿物的绚丽多彩效果。紫外线的光范围分为四类：远紫外线（25nm至250nm）；紫外线。短波（250nm至300nm）; 中波（300nm至350nm）; 和长波（350nm至400nm）。其中，短波和长波紫外线是荧光矿物收集者最感兴趣的紫外线。尽管有相当数量的矿物对长波（也称为黑光）产生响应，但百分之九十的矿物对短波辐射的响应最为强烈。某些矿物质会对两者产生响应，两种波长发出的不同颜色可以帮助识别样本。

紫外线除了在荧光矿物质中引起彩色显示外，还有许多用途。短波，中波和长波紫外线在许多实验室应用中至关重要，例如色谱法和生物样品分析。短波和中波紫外线可杀死许多细菌，因此可用于灭菌以及各种医学治疗。地毯清洁公司使用长波紫外线来定位宠物尿渍（您也可以这样做，使用无底盒或黑色悬垂布提供必要的黑暗度）。紫外线的安全性，法医和工业质量控制应用很常见。

荧光矿物质

在紫外线灯的照耀下，许多普通物品发出荧光：牙齿，白衬衫，许多墨水和塑料，曲轴箱油，一些木材-甚至是蝎子，这一事实给不只一个探矿者带来了麻烦，他们在沙漠中寻找沙漠。晚！但是荧光矿物质的反应激发了收藏家的兴趣。方解石在通常的日光下通常是暗淡的白色，可能发出红色或橙色，粉红色或绿色的荧光。萤石本身很漂亮，但在紫外线下确实能恢复活力：亮的淡黄色，深绿色，蓝绿色，蓝色，紫蓝色，红紫色，橙色，奶油色和蓝白色。

矿物显示的荧光颜色变化通常归因于被称为活化剂的杂质。活化剂（在某些情况下，一种或多种活化剂）吸收紫外线，并在反应中发出可见光（彩色）和少量热量。活化剂锰会使方解石发出红色或橘红色荧光。萤石，深绿色；和氟磷灰石，黄色。铀酰离子可使大多数矿物发出绿色荧光。

有时，活化剂电子会停留在高能状态，并且在关闭紫外线后，矿物会继续发光。这称为磷光。在新泽西州富兰克林发现的威廉石品种是荧光和磷光矿物的绝佳例子，但还有许多其他种类。方解石通常是磷光的。对一些带有紫外线的矿物质加热（例如，将其短暂地放在热水龙头下）将使磷光更加显着。

紫外线灯如何工作

用于此爱好（或激情！）的灯在外观和功能上与普通荧光灯相似-充满氩气和少量汞的玻璃管。电流使水银发出紫外线。在普通的荧光灯中，灯管内部的涂层将其转变为可见光。短波管是无涂层的，由特殊的石英或高硅玻璃制成，这是大多数类型的玻璃短波传输的一种。长波管是普通玻璃，上面涂有长波发磷光体，而不是可见光。

短波紫外线灯和长波紫外线灯都需要滤光片，以阻挡否则会产生的少量可见光。短波紫外线灯使用一个单独的滤镜，该滤镜必须由一种特殊的玻璃制成（这是使短波灯比长波灯更昂贵的因素之一）。一些长波管将过滤器作为玻璃的一部分，而其他一些则使用单独的廉价过滤器。

收集荧光矿物质

通常，获取标本的最令人满意的方法是自己找到标本。一个很好的开始方法是加入当地的摇滚俱乐部。如果没有可用的书，或者您更喜欢单独阅读，那么一本有关荧光矿物的好书，再加上对您所在地区的猎狗指南，可以帮助您入门。始终确保您知道计划收集的区域的状态，并在需要时获得许可！荧光矿产学会是创业者和有经验的勘探者的良好资源。

可充电6瓦紫外线灯小型手持式6瓦紫外线灯方便携带。当您是新手时，它们是一个不错的起点。更大的6瓦掌上电脑这将使坚定的探矿者更加满意，因为它们会在几英尺远的距离内触发标本中的荧光，这在夜间出门狩猎时会大有裨益。多波段或组合紫外线灯使用户可以在短波和长波之间切换（LEAC-280L)。尽管可以预期紫外线输出会有所降低，但这可以大大节省设备成本。

对UV矿物探矿机有用的大多数其他工具是标准的猎犬猎犬：锤子，凿子，撬杆，野外集尘袋，安全设备等。安全眼镜或护目镜特别有用，因为它们可以保护您的眼睛免受短波辐射和碎石的侵害。当然，晚上旅行时，优质的手电筒应与紫外线灯一起放入野外旅行袋或口袋中。

在白天进行勘探时，需要某种方式来创建用于测试可能的荧光样本的黑暗空间。尽管黑色塑料片做得相当不错，而且重量轻且价格便宜，但可以使用商用观察袋。

包装奖品时（在将奖品放入野战包之前应做的事，以防止其被砸伤），请先将其包装在保鲜膜中，或者确保已对打算使用的报纸进行了测试与您的短波和长波灯一起使用，用于荧光染料。

请记住，当您晚上收集时，要小心不要捡起任何发光的蝎子！

使用紫外线灯的提示

LEC-180L/12手持式紫外线灯在12伏直流电或直流电下运行。实际上，这意味着管中的一根细丝会先于另一根磨损。如果在输出开始变暗时反转灯管，则可以延长其寿命。

要记住的另一件事-这次是安全建议-短波紫外线是引起晒伤的波长。虽然很难从业余爱好者的灯中获得足够的曝光来灼伤皮肤，但是长时间直视短波灯无疑会导致眼睛暂时受损。避免这种情况！只要将短波样本放在玻璃杯中（但不要放在鱼缸中！鱼没有眼睑，因此根本就不会受到短波辐射的灼伤），则可以安全地显示短波样本。

美国路阳上海公司提供多种波段的紫外线灯，欢迎大家咨询选购。

UV LIGHT AND FLUORESCENT MINERALS

Ultraviolet (or UV) is light with wavelengths shorter than that of visible light, measuring from about 25nm (nanometers) up to 400nm. Although we can't see ultraviolet light, when visible light is dim or absent we can see ultraviolet's brilliantly colorful effect on fluorescent minerals.

The ultraviolet range of light is divided into four categories: far ultraviolet (25nm to 250nm); short-wave (250nm to 300nm); mid-wave (300nm to 350nm); and long-wave (350nm to 400nm). Of these, short-wave and long-wave UV are the ones of most interest to collectors of fluorescent minerals. Ninety percent of these minerals respond most strongly to short-wave radiation, though a respectable number respond to long-wave (also known as black light). Some minerals respond to both, and the different colors brought out by the two wavelengths can help identify a specimen.

Ultraviolet light has many uses other than causing colorful displays in fluorescent minerals. Short-wave, mid-wave, and long-wave UV are vital in numerous laboratory applications, such as chromatography and the analysis of biological samples. Short-wave and mid-wave UV kill many bacteria, and so are used in sterilization, as well as for a variety of medical treatments. Carpet cleaning companies use long-wave UV to locate pet urine stains (you can do this too, using a bottomless box or black drape to provide the necessary darkness). Security, forensic, and industrial quality control applications for ultraviolet light are common.

Fluorescent Minerals
Under the rays of a UV lamp many ordinary items fluoresce: teeth, white shirts, many inks and plastics, crankcase oil, some woods -- even scorpions, a fact which has caused problems for more than one prospector who was out hunting the desert at night! But it is the response of fluorescent minerals that excites the interest of collectors. Calcite, which is often a dull white in ordinary daylight, may fluoresce red or orange red, pink, or green. Fluorite is pretty on its own, but really comes alive under UV: bright pale yellow, deep green, blue-green, blue, violet-blue, red-violet, orange, cream, and bluish white.

The fluorescent color variations displayed by a mineral are generally due to impurities known as activators. The activator (or activators, in some cases) absorbs ultraviolet radiation, and in reaction emits a combination of visible light (color) and minute amounts of heat. The activator manganese makes calcite fluoresce red or orange-red; fluorite, a deep green; and fluorapatite, yellow. The uranyl ion makes most minerals in which it is found fluoresce some shade of green.

Sometimes the activator electrons get stuck in their high-energy state, and the mineral will continue to glow after the UV light is switched off. This is called phosphorescence. The variety of Willemite found in Franklin, NJ is an excellent example of a mineral that is both fluorescent and phosphorescent, but there are many others. Calcite is often phosphorescent. Applying heat to some UV-charged minerals (by holding them briefly under a hot water tap, for example) will make the phosphorescence even more dramatic.

How UV Lamps Work

The UV lamps used for this hobby (or passion!) are similar in appearance and function to ordinary fluorescent lights -- glass tubes filled with argon gas and a little mercury. Electrical current causes the mercury to emit ultraviolet light. In the ordinary fluorescent lamp, a coating on the inside of the tube turns this into visible light. Short-wave tubes are uncoated, and made of a special quartz or high-silica glass, as most kinds of glass block short-wave transmission. Long-wave tubes are regular glass coated with a long-wave-emitting phosphor instead of a visible light-emitting one.

Both short-wave and long-wave tubes require filters to block the small amount of visible light the tubes would otherwise produce. Short-wave tubes use a separate filter, which must be made of a specialized kind of glass (one of the factors that makes short-wave lamps more expensive than long-wave ones). Some long-wave tubes incorporate the filter as part of the glass, while others use a separate, inexpensive filter.

Collecting Fluorescent Minerals
Often the most satisfying way of acquiring specimens is to find them yourself. One good way to start is to join a local rock club. If none is available, or you prefer to go it alone, a good book on fluorescent minerals, combined with a rockhounding guide to your area can get you started. Always be sure that you know the status of the area where you plan on collecting, and get permission when it is needed! A good resource for both the beginning and the experienced prospector is the Fluorescent Mineral Society.

Rechargeable 6 watt UV lampSmall handheld 4 watt UV lamps are convenient and easy to carry. They are a good place to start when you are new to the hobby. The larger 6 watt handhelds will be more satisfying to the committed prospector, as they will trigger fluorescence in specimens from several feet away, a great boon when you are out hunting at night. Multiband or combo lamps allow the user to switch between short-wave and long-wave light. This can provide a significant savings in the cost of your equipment, though some decrease in ultraviolet output can be expected.

Most of the other tools useful to the UV mineral prospector are standard rockhounding tools: hammers, chisels, pry bar, field bag, safety equipment, and the like. Safety glasses or goggles are particularly useful, as they will protect your eyes from short-wave radiation as well as flying rock chips. A good flashlight should go into your field bag or pocket along with your UV lamp(s) for night trips, of course.

Some way of creating a dark space for testing possible fluorescent specimens is necessary when prospecting during daylight hours. Commercial viewing bags are available, though a black plastic sheet does a pretty decent job and is both lightweight and inexpensive.

When wrapping your prizes (which you should always do before you put them in your field bag, to protect them from getting banged up), either wrap them first in plastic wrap, or be sure that you've tested the newspaper you plan to use with your short-wave and long-wave lamps, for fluorescent dyes.

Remember when you're collecting at night to be careful to not pick up any prettily glowing scorpions!

Hints for Using UV Lamps
Handheld UV lamps run on 12 volt DC, or direct current. In practical terms this means one of the filaments in the tube will wear out before the other. If you reverse the tube when the output begins to dim, you can extend its life.

Another thing to keep in mind -- a safety suggestion this time -- is that short-wave UV is the wavelength that causes sunburn. While it is very hard to get enough exposure from a hobbyist's lamp to burn skin, looking directly into a short-wave light for an extended period of time can certainly cause temporary damage to your eyes. Avoid this! Displaying short-wave specimens is safe as long as you have them behind glass (but not in a fish tank! Fish have no eyelids, and thus no protection at all from being burned by the short-wave radiation)