Collecting and Displaying Fluorescent Minerals with an Opal Emphasis
By Jim Pisani
EditorAmerican Opal Society
Photo by Jan Wittenberg
2 Outline What is Fluorescence? What is Ultraviolet Light?
Where Fluorescence used?What are Fluorescent Minerals?How do I collect them?Where do I collect them?Clubs, informationDemonstration of Fluorescence
3 What is Fluorescence?Fluorescence is the property of giving off light at a one emission wavelength (color) when illuminated by light of a different excitation wavelength (color).Excitation source can be a variety of wavelengths – e.g. - blue light, infrared light, ultraviolet light (typical).Emission wavelength can be many different ones, but always lower than the excitation wavelengthPhosphorescence is where energy is absorbed by a substance is released slowly in the form of light.This is used for "glow-in-the-dark" materials which are "charged" by exposure to light.Absorbed radiation may be re-emitted at a lower intensity for up to several hours
4 Fluorescent is a subatomic change of states
Fluorescence occurs when a molecule, atom or nanostructure relaxes to its ground state (lower energy) after being electrically excited.
5 The Ultraviolet Spectrum
6 What is Ultraviolet Light?
High energy light at a wavelength outside of visible spectrumTypes of ultravioletLong Wave (UVA)Present in SunlightTypical “black light” seen in Disco’s, etc.
7 What is Ultraviolet Light?
Short Wave (UVC)Not present in SunlightMost energetic fluorescentMedium Wave (UVB)Present in SunlightLeast fluorescent wavelengthUsed in DNA Analysis
8 Where is Fluorescence used?
Fluorescent LightingWhite LED lightsTV’s (tube types)GermicidalLeak detectionErasing EEPROMs
9 Where is Fluorescence used
Cure epoxy, paint, etc.Readmission ControlLaundry detergentforensic investigationMedicine - Cellular imaging, DNA analysis, etc.Counterfeit currency detectionGems & MineralProspecting for various mineralse.g. scheelite (ore of tungsten, opal)“Noodling” for opalCollecting and Display cases
10 UV Lamps Lamp Uses Permanent (Display) Prospecting (portable)
Large, require lots of power, but can have lots of UV lightMain use in display cases, disco’s, etc.Prospecting (portable)Small, portable, light weight, for prospecting in “the bush”
11 UV Lamps Lamp Types Fluorescent tubes UV LED Flashlights
By far the most commonAdvantages – powerful, available at short, medium and long wavelengthsDisadvantages - Bulky, power use, expensiveUV LED FlashlightsAdvantages – light weight, inexpensiveDisadvantages – low power, availability at shorter wavelengths at a reasonable priceHowever, getting more powerful and cheaper
12 Build your own Portable UV Lamp
Cheaper for portable lampsMost expensive component - Hoya U-325C FilterShort wave UV bulb - can use a germicidal lampLong wave, UV bulb - available from a number of manufacturersPlans: see Fluorescent Mineral Yahoo GroupNeed Electronic BallastNeed large batteryCarry in backpackCLF Spotlight CaseReflector can be important
13 Homemade Portable UV Lamp – Version 1
14 Homemade Portable UV Lamp – Version 2
15 Homemade Portable UV Lamp – Version 3
Most Inexpensive option - 12 volt portable CFL lampBayco SL-912TAlmost everything is thereReplace lights with UV bulbsRemove plastic cover and glue filter onto coverContains own electronic ballastDisadvantages – reflector non-optimal
16 Display Cabinets Usually a homemade affair
Lamps on top hidden from viewConstruct in such a way to vent heatGlass or plastic (Lexan) can be used to shield viewers from Ultraviolet lightLexan is bestprevents UV from lighting up surroundings, distracting from the specimensGlass will have a glowing side and a non-glowing sidemake sure glowing side is the external sideLine inside with black feltCan be shortwave, longwave, or both
17 Typical Minerals that Fluoresce
WillemiteFluoriteSodaliteWerneriteCalciteOpalScheeliteMinerals may react to long wave differently than short waveDifferent intensitiesDifferent colorsShort wave fluorescence is usually more energetic
18 Different responses to different wavelengths
Photo by HP GarlandFMS
19 Where can I get Fluorescent Minerals?
Buy on eBayBuy at Gem & Mineral ShowsTo find shows near you, go to:Trade with other collectorsCollect your own
20 Where can I collect Fluorescent Minerals?
Many areas contain local fluorescent minerals, but here are some of the famous onesFranklin, New JerseyMount Saint-Hilaire, Quebec, CanadaArizona, Nevada, & CaliforniaPurple Passion Mine, Wickenburg, ArizonaVirgin Valley, NevadaThe Ilimaussaq Complex, South Greenland
21 Franklin, New JerseyThe location of a large complex zinc deposit and mined since the 18th century, contains some of the most complex silicates in the worldMines are now closed by plenty of dumps for diggingUnique Chemistry has made some of the minerals the most fluorescent in the worldWillemite, calcite, hardystonite, etc.Many minerals are found no where else in the world
22 Typical Franklin Fluorescent Minerals
Nice 4-color: willemite, calcite, clenohedrite and hardstoniteCalcite and WillemiteWillemite and Calcite
23 Mount Saint-Hilaire, Quebec, Canada
Alkaline intrusion complex – very rare geologicallyOver 51 fluorescent minerals found at this locationSodalite, Albite, Apatite, Polylithionite etc.Polylithionite and albite under SWGenthelvite crystals under SW
24 Arizona, California & Nevada
Willemite, Calcite, Fluorite, Aragonite, from the Purple Passion Mine, Wickenburg, ArizonaCommon opal, from Virgin Valley, Nevada
25 The Ilimaussaq Complex
The Ilimaussaq Complex is a unique geological intrusion in an area of Southern Greenland that is free of iceNear the town of NarsaqThe Tunulliarfik and Kangerluarsuk Fjords cuts through the middle of the Ilimaussaq ComplexSome of the most unusual minerals in the world can be found hereGem quality ussingitemassive veins of sodalite, including tenebrescent green sodalitebrilliant assortments of multi-color tugtupitedeeply tenebrescent green sodalite
26 The Ilimaussaq Complex
27 Greenland Fluorescent Minerals
28 Opals and Fluorescence Australian Opal
Most Australian Opal will fluoresce better to long wave than short waveMost boulder opal does not fluoresceSome Lightning Ridge opal will fluoresce whiteSome Andamooka opal and opal matrix will fluoresce whiteMost Coober Pedy opal will fluoresce whiteMost Mintabe opal will fluoresce whiteMost Lambina opal will fluoresce white
29 Opals and Fluorescence American Opal
Most American Opal will fluoresce bright greenTecopa Opal will fluoresce more strongly to short waveHyalite opal some of the brightest fluorescent mineralsVirgin Valley Common opal – very bright – high concentrations of uraniumPrecious opal does notWyoming common opal – very bright green and orangeSpencer opal – weak white response to SW and LWIce cream opal – strong green rsponse to SW, LW
30 Other Opal Ethiopian opal does not fluoresce
Brazilian opal – some, mild LW, some, Strong green SWPeruvian opal - ?Whitesail opal - no fluorescenceMexican Opal – no fluorescence
31 What Causes Minerals to Fluoresce?
Pure minerals usually do not fluoresceExceptions – Scheelite, powellite, cerussiteActivators – trace elements that enable fluorescenceManganese, lead, uranium, rare-earth elements, especially europiumQuenchers – their presence can stop fluorescencecobalt, and nickel, and to a lesser extent, copper
32 A word on Safety… Ultraviolet light can be dangerous
Long wave is safe (e.g. Black Light in Disco’s)Medium wave and short wave ultraviolet light can burn the skin and eyes and increase risk of skin cancerDamage is based on exposure timeALWAYS use eye and skin protection with medium and short wave ultraviolet lightShortwave ultraviolet is almost completely stopped by most forms of glass or plastic.ALWAYS avoid staring directly at a UV light source
33 UV DemonstrationIf you wish to participate, please wear glasses or the plastic frames provided and do not stare into directly the UV lightVarious minerals on displayOpal from Australia, America’sFranklin calcite and willemiteBright red and very bright green under SWTugtupite from GreenlandOrange under LW and red under SWExhibits tenebrescent – the ability of UV to semi-permanently change the actual color of the mineralWernerite from CanadaBright yellow under LWMisc
34 The End
35 Backup Slides
36 Germicidal Low Pressure Mercury Lamp Spectrum
Most of the energy is at 254 nm, right in the middle of UVC bandSome other energy in UVA and violet spectrumRequires visible blocking filter to block violet light, which would overshadow the fluorescence
37 Ultraviolet Transmitting, Visible Absorbing Filter
Hoya U-325C FilterSpectrum cuts off visible lightExpensive - $170 for 6” x 6” glass plateCut in half for two lampsHave limited lifespan due to “solarization”
38 Germicidal Low Pressure Mercury Lamps
Designed to kill microbes in AC’s wands, etc.Germicidal – kills bacteria, viruses, dust mites, etc.Clear, no phosphorsMade out of quartz, not glass
39 UV Lamps Where to get them? Purchase new Purchase used
Retail Brands – most carry portable and displaySuperbright II -Way Too Cool lamps -Ultraviolet Lighting Products “Ultralight 2002” -LED Lamps -I added a “Woods Glass” filter to black out the visible light (photo stores carry them)Spectroline -Cole Parmer -Purchase usedeBay Internet Auctions –Surprisingly cheap for surplus scientific equipmentLarge Display lampsTransilluminators (used for DNA research)Can salvage the filter from themUsually medium waveGem & mineral shows, Want ads
40 Clubs, Information Fluorescence Mineral Society
World wide organizationLarge Local Southern California chapterFluorescent Mineral Yahoo! Group – Online BlogAmerican Opal SocietyRecommended Books:The World of Fluorescent Minerals, by Stuart SchneiderCollecting Fluorescent Minerals, by Stuart Schneider