- The Cochise County Rock
- Monthly Newsletter of the Sunsites Gem & Mineral Club
- http://sites.google.com/site/cochisecountyrock/
- http://picasaweb.google.com/cochisecountyrock/
- "Finding and Grinding Rocks in Cochise County, Arizona since 1965"
- March 2011
- This issue edited by Don Hammer
- ____________________________________________________________________________________
- March Field Trip
- We will go to the St. David area for fluorescent minerals. Since we need a moonless night, the March field trip will be on Saturday March 5. Meet at Ed Fenn's store - Benson Feed & Supply - at 5:30 pm to leave at 5:45 pm. Take the 306 exit off I-10, turn left to the stop sign; turn right on 4th and watch for the Self Storage Warehouse on the right. At the warehouse turn right onto the frontage road and then left past the Nancy Leverenz vet clinic to the feed store. Bring water, snacks, a black light (UV short wave preferred), bags or pails, pickup (reach) tools, flashlights with fresh batteries, warm clothing and rock breaking tools. Sunset is at 6:20 so we will be on site until 8 - 8:30 pm.
- The next General Meeting of the Sunsites Gem & Mineral Club is on Monday March 14, 2011 at 7:00 pm at the Sunsites Community Center. The program will start at 7 with the business meeting to follow. Geomorphologist Glenn Minuth will show us why the San Pedro Valley is recognized as a world-class area for understanding the fauna of the Plio-Pleistocene Epochs.
- Ice Age Animals and Early Human Fossils of the San Pedro Valley
- The abundant fossil evidence of the Plio-Pleistocene animals during the last 5-6 million years in the San Pedro Valley has yielded an excellent record of early man and extinct mammals.
- Pronghorns, rhinos and camels were plentiful. Giant beaver and long-horned bison were widespread. Columbian mammoths, shrub oxen, giant ground sloths and huge armadillos were common. Others included capybara, jaguars, hyenas, bears, the three-toed horse, mastodons, llamas and seven species of rabbits. Many molluscs, fish, amphibians, reptiles, birds and smaller mammals also occurred in the San Pedro. During the early Ice Age in North America, thousands of years of large-scale climatic changes from very warm to very cold climates caused wide spread extinction for some animals but created favorable environments for others. Capybara, rhinos, tapir, elephants and camels thrived when the climate was much hotter than today whereas mammoths, wolverine and shrub oxen found long periods of much colder climates to their liking. Toward the end of the Pleistocene, climatic changes decreased producing the climate that we know today and this was when early man appeared in the San Pedro. Paleo-Indian remains from both the Clovis and Cochise cultures have been found there. In fact, the valley has yielded the best fossil record of early man and extinct mammals known in North America. Readers are reminded that the Omnibus Public Land Management Act of 2009 prohibits collection of vertebrate fossils on Federal lands without proper permits.
-
- The drama of Pleistocene life is notably preserved in the sedimentary rock record of the region especially during the last Ice Age. Glenn will discuss the fossil evidence for an assemblage of giant mammals, many of which are now extinct. Why did some of these mammals disappear while some survived to the present day?
- Glenn Minuth is a Department of Army civilian employed as project manager for the Network Enterprise Technology Command at Fort Huachuca. His Bachelor's and graduate degrees are in geography with specialties in cartography, geomorphology, remote sensing, and geology. Other areas of academic focus were biogeography , weather/climate, and soils. Glenn taught geography and geology in the Life and Physical Science Department of American River College, Sacramento, California, for seven years. He was an instructor in geography and geology for 10 years at Cochise College in both credit and non-credit programs.
- Minutes of the General Meeting on February 14, 2011
- Jack Light, Vice-President, called the meeting to order at 7:00 and opened the meeting by welcoming visitors of which there were several.
-
- First item on the agenda was the approval of the previous Meeting's minutes. With no discussion, the motion was made and seconded to accept the Minutes as published and all were in favor.
-
- Second item was the Treasurer's Report given by Walter Sigel. A motion was made and seconded to accept the report. All voted in favor.
-
- The Field Trip report was made by Henri Van den Bos. The January Field Trip was an excursion off Cascabel Road where very good specimens of yellow and red jasper were plentiful. A highlight was observing
- the site of prehistoric tracks made by a large animal of unknown identity.
-
- This month's Field Trip will be to Rock Creek in the Chiricahuas to look for chalcedony and fine layered sedimentary rock. The Club will meet in the Sunizona restaurant parking lot at 9:00 Saturday morning, February 19th.
-
- The Field Trip slated for March 5th will be a night excursion to observe fluorescence in rocks. The Club will meet at Ed's Feed Store
- 5:30 PM. Those members who own black lights are asked to bring them along.
-
- Before breaking for intermission, Jack thanked Patricia Cavallero and
- Diane Brower for providing refreshments.
-
- After intermission, Renate LeDuck was awarded top prize for the best jasper specimen from the February Field Trip to Cascabel.
-
- After the raffle, the Club once again welcomed Michael Roegner, renown stone knapper who demonstrated his facility and knowledge of shaping knife blades from stone. Through the course of his demonstration he explained the interesting history and facets of stone knapping and thoroughly answered the many questions asked throughout the evening.
- February Field Trip
- Due to access problems and the weather, we changed the field trip location and went to Rolf and Mary Luetcke's Museum near Benson. Some 14 members enjoyed an excellent tour of their tremendous collection of rocks, jewelry, fossils, artifacts, insects and reptiles. They have over 15,000 specimens of different minerals most of which Rolf has micro-photographed. Rolf's demonstration of mineral fluorescence under long wave and short wave UV light was striking. We thank Rolf and Mary Luetcke for conducting a fascinating tour of their extensive collections.
- Lapidary and Silversmith Classes
- Our lapidary, silver soldering and wire wrapping classes are once again available so if you're interested call Larry Strout at 826-3991.
- Dues are due.
- Dues are $15 for individuals and $25 for a family. Bring your dues to the next meeting or mail your check to Sunsites Gem & Mineral Club, PO Box 87, Pearce, Arizona 85625. Unpaid members will be dropped.
- Club Calendar:
- March
- 5 Night Field Trip
- 14 General Meeting
- 31 Board Meeting
- April
- 11 General Meeting
- 16 Field Trip
- 28 Board Meeting
- May
- 9 General Meeting
- 14 Field Trip
- 26 Board Meeting
- June
- 4 Club Picnic
- Upcoming Regional Events
- March
- 10-13 Rockhound Roundup - the Deming Show. Jewelry, rocks, minerals, displays and demonstrations, guided field trips and auctions. Bud Daily 575-267-4399; Jerry Abbey 575-543-8915 www.dgms.bravehost.com
- 18-20
- Albuquerque 2011 Gem & Mineral Show. NM State Fair Grounds. Fri & Sat 10 am - 6 pm, Sun 10 am - 5 pm Small Admission. Paul Hlava 505-255-5478 or paulhlava@q.com
- June
- 17-19
- Tombstone Gem & Mineral Show. Fri & Sat 10 am - 6 pm. Sun 10 am - 4 pm. Free. Tombstone Territories RV Park; between MP 59 & 60 on Highway 82. Betty 520-457-9505.
- Officers for 2011
- President: Diane Dunn
- V-President: Jack Light
- Secretary: Jim Brower
- Treasurer: Walter Sigel
- Deleg-at-Large: Carl Schnabel
- Hospit Coord: Zoe Schnabel
- Field Trip Crd: Henri van den Bos
- Past Pres: Paul McKnight 775-434-8395
- Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation of a different wavelength. In most cases, emitted light has a longer wavelength, and therefore lower energy, than the absorbed radiation. However, when the absorbed electromagnetic radiation is intense, it is possible for one electron to absorb two photons; this two-photon absorption can lead to emission of radiation having a shorter wavelength than the absorbed radiation.
- The most striking examples of fluorescence occur when the absorbed radiation is in the ultraviolet region of the spectrum, and thus invisible, and the emitted light is in the visible region.
- Fluorescence has many practical applications, including mineralogy, gemology, chemical sensors, fluorescent labeling, dyes, biological detectors, and, most commonly, fluorescent lamps.
- There are many natural and synthetic compounds that exhibit fluorescence, and they have a number of applications. Some deep-sea animals, such as the Greeneye, use fluorescence.
- The common fluorescent lamp relies on fluorescence. Inside the glass tube is a partial vacuum and a small amount of mercury. An electric discharge in the tube causes the mercury atoms to emit ultraviolet light. The tube is lined with a coating of a fluorescent material, called the phosphor, which absorbs the ultraviolet and re-emits visible light. Fluorescent lighting is more energy-efficient than incandescent lighting elements. However, the uneven spectrum of traditional fluorescent lamps may cause certain colors to appear different than when illuminated by incandescent light or daylight. The mercury vapor emission spectrum is dominated by a short-wave UV line at 254 nm (which provides most of the energy to the phosphors), accompanied by visible light emission at 436 nm (blue), 546 nm (green) and 579 nm (yellow-orange). These three lines can be observed superimposed on the white continuum using a hand spectroscope, for light emitted by the usual white fluorescent tubes. These same visible lines, accompanied by the emission lines of trivalent europium and trivalent terbium, and further accompanied by the emission continuum of divalent europium in the blue region, comprise the more discontinuous light emission of the modern trichromatic phosphor systems used in many compact fluorescent lamp and traditional lamps where better color rendition is a goal.
- White light-emitting diodes (LEDs) became available in the mid 1990s as LED lamps, in which blue light emitted from the semiconductor strikes phosphors deposited on the tiny chip. The combination of the blue light that continues through the phosphor and the green to red fluorescence from the phosphors produces a net emission of white light.
- Glow sticks sometimes utilize fluorescent materials to absorb light from the chemiluminescent reaction and emit light of a different color.
- Fingerprints can be visualized with fluorescent compounds such as ninhydrin. Blood and other substances are sometimes detected by fluorescent reagents, particularly where their location was not previously known.
- Gemstones, minerals, fibers, and many other materials which may be encountered in forensics or with a relationship to various collectibles may have a distinctive fluorescence or may fluoresce differently under short-wave ultraviolet, long-wave ultra violet, or X-rays.
- Many types of calcite and amber will fluoresce under shortwave UV. Rubies, emeralds, and the Hope Diamond exhibit red fluorescence under short-wave UV light; diamonds also emit light under X ray radiation.
- Fluorescence in minerals is caused by a wide range of activators. In some cases, the concentration of the activator must be restricted to below a certain level, to prevent quenching of the fluorescent emission. Furthermore, certain impurities such as iron or copper need to be absent, to prevent quenching of possible fluorescence. Divalent manganese, in concentrations of up to several percent, is responsible for the red or orange fluorescence of calcite, the green fluorescence of willemite, the yellow fluorescence of esperite, and the orange fluorescence of wollastonite and clinohedrite. Hexavalent uranium, in the form of the uranyl cation, fluoresces at all concentrations in a yellow green, and is the cause of fluorescence of minerals such as autunite or andersonite, and, at low concentration, is the cause of the fluorescence of such materials as some samples of hyalite opal. Trivalent chromium at low concentration is the source of the red fluorescence of ruby corundum. Divalent europium is the source of the blue fluorescence, when seen in the mineral fluorite. Trivalent lanthanoids such as terbium and dysprosium are the principal activators of the creamy yellow fluorescence exhibited by the yttrofluorite variety of the mineral fluorite, and contribute to the orange fluorescence of zircon. Powellite (calcium molybdate) and scheelite (calcium tungstate) fluoresce intrinsically in yellow and blue, respectively. When present together in solid solution, energy is transferred from the higher energy tungsten to the lower energy molybdenum, such that fairly low levels of molybdenum are sufficient to cause a yellow emission for scheelite, instead of blue. Low-iron sphalerite (zinc sulfide), fluoresces and phosphoresces in a range of colors, influenced by the presence of various trace impurities.
- Crude oil (petroleum) fluoresces in a range of colors, from dull brown for heavy oils and tars through to bright yellowish and bluish white for very light oils and condensates. This phenomenon is used in oil exploration drilling to identify very small amounts of oil in drill cuttings and core samples.