ALL ABOUT FLUORESCENT MINERAL LIGHTS
UV Lights For Rocks
The mineral lights needed to prospect for our magnificent glow rocks are expensive, and serious lights are only available from a few manufacturers.
There are many different kinds of lights out there; some are simply not suitable for fluorescent mineral collecting. They are usually the cheap alternative and the buyer will be greatly disappointed. For reference, an example of these types of lights is listed at the end of this page.
If you are new to the hobby you might want to learn more about UV and the various light sources (shortwave, midwave, longwave, blacklight) before diving into the review.
You can expect to pay >$240 for a reasonable portable shortwave field mineral light, and powerful home display lights can be a thousand dollars or more. There are lower cost entry level lights which will allow you to play around and learn - see if this hobby is for you. But expect to invest some money in serious lights if you catch the glowbug.
MINERAL LIGHT BASICS
ENTRY LEvEL LIGHTS
There are many entry level lights on the market. Prices range from a few $ to a ridiculous price of $150. Some are simple 4 watt blacklights. Some are garbage 390/395nm LEDs. Some low-power shortwave lights might be a way to see if you're really interested in the hobby before dropping several hundred dollars on a real light (but anything over $75 merits serious thought about a real light).
Be aware that the really cheap ones are.... cheap. Fluorescent tube blackights are longwave and really replaced by LED flashlights - fewer fluorescent minerals are found using a blacklight. Unfiltered shortwave lights are garbage.
The small 4W/6W/11W shortwave lights are very low power and will only light up a small area, in spite of outlandish claims of UV power. Some have ridiculously low-power LW/SW bulbs, and filter windows so small you'll be lucky to light up a stamp.
These lights are economical but really only "toys". If you get bitten by the "glowbug" you will soon be looking for a high-end mineral light.
The first SW light most people own is a medium power, portable shortwave field light. Battery powered, they are used to go collecting at night, at shows, club meetings etc. While there are a few low-end lights which will marginally do the job, if you're serious about collecting there are only a few companies who offer lights made for today's hobby.
UV Flashlights (or Torches)
365nm longwave LED flashlights are a must. Note that these lights must have a UV pass/visible blocking filter - a must for any light used with fluorescent minerals - even LED lights.
Convoy C8 365nm Flashlight
This light is the next generation Convoy - the Convoy Redesigned. It offers almost 3 watts of UVA output (radiant) and is unbelievably bright. Currently the best LW UV flashlight for rocks on the market.
Convoy S2+ 365nm Flashlight
A new, amazing, and affordable LW flashlight, the Convoy S2+ - replaces the need for a portable fluorescent LW light. More information in the "Equipment" section of the GlowNotes Blog. If you want a high-power UVA flashlight, this comes highly recommended. (around $22)
Shortwave and Midwave Flashlights
New in 2022 are offerings of SW and MW flashlights - 255nm and 307nm. Although relatively low power they are an excellent step forward. Stay tuned for many new products to be offered in this arena.
High wattage lights (AC powered) are used to illuminate large collections, museum displays, and other types of mineral displays. The same manufacturers who offer portable field lights also sell a complete line of the high-powered lights. Learn with your portable field light (the place to start) and apply what you've learned when it comes time to spend $700 to $1,500 on a big light...
THE ONES NOT TO BUY
Cheap, unfiltered shortwave lamps - Garbage!
Ebay is filled with SW lamps for $15 to $25 that offer up the world of fluorescence for pennies on the dollar. These lights are UNFILTERED and completely useless for the fluorescent mineral hobby. They will often be shown with a specimen of willemite/calcite from Franklin NJ and you will see a washed out glow from the rocks. That's about the only rock you'll be able to see any fluorescence in, and even those wonderfully bright fluorescent specimens will appear washed out. Even worse, some have photoshopped pics of our rocks with their lights, as if the light was causing the fluorescence.
Bottom line - if you don't see a filter on the light (a dark glass allowing only a purple/violet light to escape), don't waste your time. Our UV lights generate a lot of visible light in addition to the UV. This light must be filtered by UV pass, visible blocking filters. These filters are the most expensive part and many unscrupulous (or uneducated) sellers try to sell lights which don't have them.
Cheap, longwave (UVA) blacklight lamps and flashlights - Not much better!
NOTE: There is one exception to this. The Convoy S2+, recently marketed from China, uses a Nichia high-power 365nm LED. With a filter installed, it outperforms any longwave portable light on the market today.
Longwave lights have their place in our hobby but the first time buyer must be aware that only a small percentage of fluorescent minerals will react to longwave (LW). The bright, multi-colored specimens you see in the Nature's Rainbows photo gallery almost always require a good SW light.
Worse - there are many different types of cheap LW lights. Some are simple LED flashlights which put out more visible light than UV. Others are ordinary, low power blacklights. The first time buyer will quickly tire of these lights, and any attempt at photography will simply result in a blue blob. $20 probably won't break the bank but these are not lights for serious collectors. For more about LED UV flashlights read this Glow Notes blog post about filtered and unfiltered lights.
Fluorescent Mineral Lights - FAQ
(We wrote this FAQ many years ago. A lot has changed since, but the content is still valuable).
In the last couple of years there have been several new manufacturers and suppliers of portable UV lamps – great news for the Glowhound's hobby. But, we have not seen an independent comparison of lamps (until now), and the advice we see coming from some manufacturers is (in my opinion) misleading and borders on dishonesty. We don't have the time or resources to devote to actually testing each lamp out there and providing a side-by-side comparison, but we do have the ability to point out what you should look for when buying a field lamp. That is the purpose of this FAQ – What to look for in buying a field lamp. Please keep in mind that we only have used two lights: the SuperBright made by UV Systems and the Way Too Cool line of lamps. We have no field experience with any other lamp. We build our own lamps for use in the field and at home, but we do not sell lamps – thus we do not have a hidden agenda. We believe that competition is good for our hobby and hope that eventually someone will figure out how to build a good cheap lamp so that everyone can afford to enjoy these wonderful glowrocks as we do.
Q: What are the most important factors in considering a specific model lamp for field use?
A: A lot depends on the individual. Cost, weight, brightness, reliability and power consumption are the main concerns we would have when buying a portable lamp for field use.
Q: What do these lamps cost?
A: They range from cheap to expensive. It's up to you to shop around but there are some basic facts that you should be aware of. Most lamps use a Hoya 325c filter which is probably the most expensive component in the lamp. They all use a UV bulb, and they all have an ballast/inverter. These three items should cost each manufacturer pretty much the same – so if they have a bigger filter, or two lamps, or more watts (higher power) the costs will increase accordingly. When comparing costs make sure you compare the filter area and lamp UV wattage.
Q: I've seen a person selling an unfiltered shortwave light for mineral use on Ebay – cheap – and he claims it "outshines" all other "filtered" units.
A: HOGWASH!!!! That lamp is useless. UV tubes put out a tremendous amount of visible light. This light overwhelms the UV and washes out the fluorescent response of almost all minerals. You may be able to see the response of a very bright Willemite/calcite from Franklin but we can't think of too many more minerals that you will be able to find with an unfiltered light. This is either a scam or a terribly misinformed seller – do not buy an unfiltered light.
Q: How are these lamps powered?
A: Portable field lamps require portable power. That means a battery; the most common being a 12VDC lead acid battery (the same type of battery used in your car, only a little smaller). Batteries are rated in Amp Hours (AH). The battery typically sold for use with the Superbright is a 7AH battery. This means if the Superbright uses 1 amp per hour, the battery "should" keep it lit for 7 hours (it doesn't really work that way because a lead acid battery dies slowly as it is being used, and when the voltage drops below 10 volts, the lamp shuts down). You may get 4 or 5 hours use out of the battery. (BTW – take a look at the NiMH battery packs being offered on Ebay – they are half the weight and twice the power of a lead acid battery - or better yet, look into LiFE technology).
Q: Some manufacturers sell an "Inverter" and a battery to use their lamp in the field – what does that mean?
A: (Disclaimer - we prefer a battery operated lamp, but my DIY section on MinerShop.com shows a lamp using an inverter. If you want to save some $$$ and are willing to deal with the expense/hassle of an inverter, it's a good way to go. But battery lamps are better, but also beyond the technical capability of most DIY'ers.) That said, an inverter uses a battery to generate 110vac (house current). The lamp manufacturers who recommend this solution mean they have not taken the time (or trouble) to design a lamp for operation on 12VDC. They're using a "cop out" by asking you to buy not only the heavy clunker 12VDC lead acid battery, but now an extra piece of equipment to turn that battery voltage into 110vac so their lamp will work in the field. Why is this bad? Several reasons; first, it's an extra piece of gear to carry around, secondly another thing to break while in the field, and third – it is a terribly inefficient use of battery power. An inverter consumes power just like anything else. It takes battery power to turn that good ol' 12vdc into that nasty 110vac. Every inverter does this differently, and how good they are at it is called "efficiency". As you might expect – efficiency is the term inverter companies use to compete with each other. The higher the efficiency the better the inverter. But – it's all hogwash. It'll be real hard to figure out the true efficiency of an inverter for a given load without actually testing it. Some claim as high as 90% efficiency but we would use 70% as a good rule of thumb. This means that 30% of the battery power (amps) is used just by the inverter to "make" 110vac. So, if you have a 10AH battery (puts out 1 amp for 10 hours), it will really only put out 7 amps because the other 3 amps are used to run the inverter. Short story – inverters eat up valuable battery power. Only buy a lamp that has a DC input.
Q: What should I look for in weight?
A: That's up to you! We do most of our prospecting in the mountains of Greenland. Every ounce matters! We have no choice with our lamp – it works and it weighs. But we do have a choice in batteries. We have long ago thrown out our clunky lead acid battery and replaced it with much smaller, more powerful and much lighter NiMH battery packs, subsequently replaced by LiFE technology. But the battery is the most important factor determining weight.
Q: Every manufacturer has a different claim about brightness – what's the real story?
A: This is a hard one to answer without actually testing each lamp to prove/disprove the manufacturer's claims. Seems like a hobby organization ought to tackle this one – it would be a great service to their membership.
But – there are some common sense rules you can apply. Wattage of the lamps indicates brightness. The more watts, the brighter the lamp. Some manufacturers "overdrive" their lamps (stuff more power into them then the lamps are rated for). It's sort of like pulling a boat with a car instead of a truck – you can do it, but the car will fall apart a whole lot quicker than normal. Same with the lamp. For the record – that's ok in my book. We'd rather have a bright light where we have to replace the bulb more often, but it helps us find more glowrocks. (Some may use two lamps instead of just one – same story – just add up the watts and compare). But, it's even a little more complicated than that; it's not a simple matter of brightness (watts). You also have to factor in the type of reflector used and the design. A 13 watt lamp with a properly designed reflector would most likely outperform a 25 watt lamp with no reflector (or one that has a UV coating preventing it from reflecting UV). Worse - watts refers to the power consumption and really has nothing to do with the UV output of the lamp (that's buried deep down in the specs of each individual lamp - something UV light manufacturers don't even talk about).
Q: Anything else to consider when it comes to brightness?
Filter area – the larger the filter area, the more UV light is gonna get out! Buy the lamp with the largest filter area. Sadly, because the filter is the most expensive component in the lamp, that lamp will most likely be the most expensive to buy. If it's not, wonder why....
Q: I use my light at night on rocky terrain and fall down a lot. What should I look for in a good field lamp?
Reliability and ruggedness: Large filter area, but figure out some way to protect the very expensive filter glass so when you trip and fall, the glass has a chance of surviving.
Q: Should I get three different units – one for SW, one for MW and one for LW?
A: Sure, if you've got an unlimited budget and an SUV that's gonna carry you directly to your collecting spot. Real world: why does anyone need anything other than shortwave? We can't think of many minerals that only lights up under MW or LW (perhaps ruby - but you don't need a lamp for those). If it lights up under SW. we will most likely carry it home. Then we'll check it out under LW and MW; maybe get a nice surprise. Why carry other lamps? Why spend extra money for combo lamps? If you really think you need LW, check out one of the LW LED flashlights. They work for most LW minerals if that's all you're looking for – and are dirt cheap! (But the cheap ones are really crappy).