Revised and Updated January 2020
As you surf the web at mineral dealer sites or attend gem and mineral shows, check out the prices that decent material is selling for. If you have a hankering for collecting Fluorescent minerals, buy a good lamp and start collecting today. We are currently living in the best time to form a collection. Good fluorescent pieces are still available and prices are a fraction of what dealers are charging for crystals (measured in centimeters in size and that don't even glow) that are not as rare as the fluorescent material. Don't miss this opportunity.
Some of the rarest fluorescent minerals in the World are from the Franklin zinc mine in Franklin, NJ.
A beautiful 4 color piece from Franklin - over a pound of manganaxinite (fluoresces red SW), xonotlite (purple-blue SW), clinohedrite (bright orange SW, more on top of the piece), and willemite (green SW). Beautiful spikes of aragonite from the Sterling Hill mine, 500 foot level, Ogdensburg, Sussex County, NJ. The piece has an older collection label. The aragonite fluoresces pale green SW. It weighs 1 lb. 6.2 oz. and is 4.5 x 3.0 x 2.6 inches
Below is a 5-color combination of rare roeblingite, clinohedrite, xonotlite, and nasonite. Roeblingite fluoresces bright red, nasonite fluoresces pale yellow (bottom right corner), clinohedrite fluoresces orange, the purple-blue is xonotlite, and the few dots of green are willemite all under SW UV. It weighs 3.3 oz and is 2.3 x 1.8 x 0.5 inches
Another super rare piece from the Franklin mine is this wollastonite, margarosanite, and calcite. This is part of the "Minehillite assemblage" that was only found in a small area of the mine. Margarosanite fluoresces sky blue, wollastonite fluoresces orange, and calcite fluoresces orange-red all under SW UV. It weighs 2.0 oz and is 2.8 x 1.5 x 0.8 inches
The Franklin mine closed in 1954 and the shafts flooded and caved in. No more minerals are coming out of the mine. The Sterling Hill mine in the next town, Ogdensburg, closed in 1986 and is also flooded. These pages show fluorescent minerals from my collection and the last 8 pages include some rare pieces for sale. Living in New Jersey, we originally chose to concentrate on fluorescents from our state. Most come from the Franklin and Sterling Hill mines. As the collection grew, we found many beautiful and unusual fluorescent minerals from other places that deserved a space on the shelves of our display room so, we have included other states and countries. The For Sale pages are updated about 10 times a year.
Throughout these pages, the first photo shows the mineral under regular light while the second photo shows the mineral under short wave (SW) ultraviolet (UV) light and/or long wave (LW) UV light. There are links to other fluorescent sites, an explanation of terms, history, books on the subject, suggestions for UV lamps and such.
Note, the black light that is widely sold in party stores and Spencer Gifts and that lights up fluorescent paints and posters so nicely, will not bring out the colors in these specimens. You must use a special filtered SW Ultraviolet lamp to obtain this effect. These are sold as mineral lamps and are available in short wave, mid wave, and long wave frequencies. Sometimes they are labeled as UV-C, UV-B, and UV-A, respectively. The Books and Links section lists several sources for lamps. Mineral lamps cost anywhere from $30.00 to $400 or more. The cost difference is in the power of the lamp. The lower end UV lamps are 4 watt lights and the higher end are 15 watt lights. The biggest cost is the short wave filters which are only made by one company in the world. These are expensive pieces of special coated glass that must be made to pass only the proper frequencies (waves) of light. We have several different lamps. If you can afford it, buy a powerful lamp. A word of warning, Short Wave UV light can cause sunburn and burn the eyes. Fluorescent collectors know that you aim the lamp away from your face and when you must use the lamp for extended periods of time, wear protective eye shields or glasses that block UV rays.
Triangular genthelvite crystals from Sterling Hill mine, Ogdensburg. Sterling Hill genthelvite is usually not found as crystals. Genthelvite fluoresces green LW (upper right) and lesser green SW (bottom photo). Calcite fluoresces orange-red SW. The piece is 1.5 x 1.3 x 0.6 inches
The most easily recognized pieces from the Franklin and the nearby Sterling Hill mines are sometimes referred to as Christmas calcites or crazy calcites. The two below are calcite (fluorescent orange-red SW) and willemite (fluorescent green SW). The black pieces are franklinite and the reddish bits are zincite or sometimes andradite garnet. The calcite and willemite from these mines situated at the northwest corner of New Jersey, glow with a color and intensity that is not found anywhere else. This area of New Jersey has more varieties of minerals (about 400) than anywhere in the world. Mineral collectors make pilgrimages to these sites. The area also is the source of about 91 fluorescent minerals, also more than anywhere else in the world. On page 6 are links to the Franklin zinc mine and the Sterling Hill mine that are now run as museums.
When it comes to willemite and calcite, which are very common at Franklin and Sterling Hill, the better pieces have interesting variations on the willemite and calcite arrangement. For example, the piece below left has veins of graphite, crystals and veins of willemite (green) criss crossing the calcite (orange-red). The piece on the right has a large vein of calcite dividing brown willemite. Willemite can be found in many daylight colors such as brown, black, yellow, green, or white. Brown willemite is often called "troostite". Once the SW lamp hits them, the willemite green makes its presence known.
It is interesting that calcite can be found that glows various shades of red or sometimes does not fluoresce at all. One rock may have both fluorescent and NF varieties of calcite in it. The mines at Sterling Hill and Franklin are only 2.5 miles apart. The fluorescence in most of the Franklin and Sterling Hill pieces is caused by minute amounts of other minerals called "activators". Sometimes the activator is lead, uranium, or most often in the New Jersey rocks, the activator is manganese. None of the pieces shown here gain their fluorescence from uranium and none of them are radioactive. There are also "quenchers" of fluorescence. If they are present in often the tiniest amount, the rock will not fluoresce. Iron is a known quencher, however some that contain iron, such as sphalerite and albite, can fluoresce.
This incredible piece contains two forms of roeblingite (one of the rarest and most sought after fluorescent minerals) - a china-like nodule and a plaster of paris-like coating. The bottom view is the underside of the specimen. Roeblingite fluoresces bright red SW. The orange is clinohedrite, the purple is xonotlite, and the green is willemite (all under SW UV). It weighs 9.0 oz. and is 3.5 x 2.0 x 1.5 inches
One of my favorite pieces - Pectolite, margarosanite, prehnite, and willemite from the Franklin mine. Beautiful and rare. Pectolite fluoresces soft orange SW, margarosanite fluoresces white SW, prehnite fluoresces lavendar SW, and willemite is green SW. It weighs 4.5 oz and is 2.4 x 1.8 x 1.8 inches.
Copyright 2016 through 2020 by Stuart Schneider. Do not use any parts of these pages without written permission.