Hey rockhounds, check out these awesome periodic table ties! The cool factor on these is clear off scale! Needless to say, these ties are an absolute must have for every chemistry teacher or professor. These turned up in Mikon's room at the Ramada Limited show and after inquiring I learned that Mikon is making them. They're going for $18 each or 10 for $130.
Mikon, Ramada Limited (formerly La Quinta Inn) Room 169 - WWW: www.mikon-online.com Email: email@example.com Steinslieth 11, D - 37130 Klein Lengden, Germany - Phone: +49 - (0) 5508 - 97 44 70 Fax: +49 - (0) 5508 - 97 44 71
Not to be outdone in the cool factor department is Kasper von Wuthenau, who has a table set up in the courtyard at the Arizona Mineral and Fossil Show at the Vagabond Plaza Hotel (formerly the Ramada Inn), where he is offering the real deal in the way of elements as well as a number of other geological specimens very high on my cool factor scale.
I first met Kasper at last year's Show during the course of purchasing some inexpensive meteorite specimens from the Nantan and NWA 869 falls from him. He showed some samples of elements then and told me he would be back this year with a broader spread of samples of the elements. I had never actually laid my own eyes before on some of the material Kasper was showing at the 2003 Show, so I made a point of returning to his table this year to check out his offerings.
Kasper brought one complete set of samples of the natural elements to the Show this year, which he reported had already been snapped up by the University of Arizona's Department of Geosciences before I made it by to visit with him. If you are interested in a complete set of the elements, Kasper can assemble and provide them. Depicted at left is one of the cases on Kasper's table containing samples of elements and other samples and specimens of elemental material were distributed about his table.
Shown above left are native copper nuggets from the Caledonia Mine, Ontonagan, Michigan. Note the quarter providing scale. The largest specimens were approximately 3 inches across. These were offered for $20 each.
Copper is reddish and takes on a bright metallic luster. It is malleable, ductile, and a good conductor of heat and electricity (second only to silver in electrical conductivity). Copper occasionally occurs natively, and is found in many minerals such as cuprite, malachite, azurite, chalcopyrite, and bornite. Large copper ore deposits are found in the U.S., Chile, Zambia, Zaire, Peru, and Canada. The most important copper ores are the sulfides, the oxides, and carbonates. From these, copper is obtained by smelting, leaching, and by electrolysis.
The electrical industry is one of the greatest users of copper. The cooper alloys brass and bronze are very important. American coins utilize copper alloys and gun metals also contain copper. Copper has wide use as an agricultural poison and as an algaecide in water purification. Copper compounds, such as Fehling's solution, are widely used in analytical chemistry tests for sugar. Here is more information regarding the properties of the element Copper.
Shown above right are native Bismuth nuggets from Bolivia. These were offered at $1.50 per gram.
Bismuth is a white, crystalline, brittle metal with a pinkish tinge. It occurs in a native state. Bismuth is the most diamagnetic of all metals, and the thermal conductivity is lower than any other metal with the exception of mercury. It has a high electrical resistance, and has the highest Hall effect (greatest increase in electrical resistance when placed in a magnetic field) of any metal. The most important ores are bismuthinite and bismite. Peru, Japan, Mexico, Bolivia, and Canada are major bismuth producers. Much of the bismuth produced in the U.S. is obtained as a by-product in refining lead, copper, tin, silver, and gold ores.
With other metals such as tin, cadmium, etc., bismuth forms low-melting alloys which are extensively used for safety devices in fire detection and extinguishing systems. Bismuth is used in producing malleable irons and is finding use as a catalyst for making acrylic fibers. Bismuth is also used as a thermocoupling material, and has found application as a carrier for fuel in nuclear reactors. Its soluble salts are characterized by forming unsoluble basic salts on the addition of water, a property sometimes used in detection work. Bismuth oxychloride is used extensively in cosmetics. Bismuth subnitrate and subcarbonate are used in medicine. Here is more information regarding the properties of the element Bismuth.
Shown above left are refined Vanadium samples which were offered at $6 per gram.
Vanadium is found in more than 50 different minerals among which are carnotite, roscoelite, vanadinite, and patronite as important sources of this metal. Vanadium is also found in phosphate rock and certain iron ores, and is present in some crude oils in the form of organic complexes. It is also found in small percentages in meteorites. Commercial production from petroleum ash holds promise as an important source of Vanadium.
Pure vanadium is a bright white metal that is soft and ductile. It has good corrosion resistance to alkalis, sulfuric and hydrochloric acid, and salt water, but the metal oxidizes readily above 660°C. Vanadium has good structural strength and a low fission neutron cross section, making it useful in nuclear applications. Vanadium is used in producing rust resistant and high speed tool steels. It is an important carbide stabilizer in making steels. About 80% of the vanadium now produced is used as a steel additive. Vanadium foil is used as a bonding agent in cladding titanium to steel. Vanadium pentoxide is used in ceramics and as a catalyst. Vanadium is also used to make superconductive magnets. Here is more information regarding the properties of the element Vanadium.
Shown above right are vials of 99.99% pure silver which were offered at $18 each. Kasper said the weight of the silver in them averaged about 13-14 grams each.
Pure silver has a brilliant white metallic luster. It is a little harder than gold and is very ductile and malleable. Pure silver has the highest electrical and thermal conductivity of all metals, and possesses the lowest contact resistance. It is stable in pure air and water, but tarnishes when exposed to ozone, hydrogen sulfide, or air containing sulfur. The alloys of silver are important.
Silver occurs natively and in ores such as argentite and horn silver; lead, lead-zinc, copper, gold, and copper-nickel ores are principal sources. Mexico, Canada, Peru, and the U.S. are the principal silver producers in the western hemisphere. Silver is also recovered during electrolytic refining of copper. Commercial fine silver contains at least 99.9% silver. Purities of 99.999+% are available commercially.
Sterling silver is used for jewelry and silverware where appearance is paramount. This alloy contains 92.5% silver, the remainder being copper or some other metal. Silver is of the utmost importance in photography, about 30% of the U.S. industrial consumption going into this application. It is used for dental alloys. Silver is used in making solder and brazing alloys, electrical contacts, and high capacity silver-zinc and silver-cadmium batteries. Silver paints are used for making printed circuits. Silver is used in mirror production and may be deposited on glass or metals by chemical deposition, electrode position, or by evaporation. When freshly deposited, silver is the best reflector of visible light known, but is rapidly tarnished and loses much of its reflectance.
Silver fulminate, a powerful explosive, is sometimes formed during the silvering process. Silver iodide is used in seeding clouds to produce rain. Silver chloride has interesting optical properties as it can be made transparent; it also is a cement for glass. Silver nitrate, or lunar caustic, the most important silver compound, is used extensively in photography. Silver for centuries has been used traditionally for coinage by many countries of the world. In recent times, however, consumption of silver has greatly exceeded the production. Here is more information regarding the properties of the element Silver.
Shown above left is a tray of gallium crystals, note the quarter providing scale. Above right is a closer view of the largest crystal. These gallium crystals were offered at $12 per gram.
Ultra-pure gallium has a beautiful, silvery appearance, and the solid metal exhibits a conchoidal fracture similar to glass.
Gallium is one of four metals -- mercury , cesium , and rubidium which can be liquid near room temperature and, thus, can be used in high-temperature thermometers. It has one of the longest liquid ranges of any metal and has a low vapor pressure even at high temperatures. High-purity gallium is attacked only slowly by mineral acids.
Gallium wets glass or porcelain and forms a brilliant mirror when it is painted on glass. It is widely used in doping semiconductors and producing solid-state devices such as transistors. Magnesium gallate finds use in commercial ultraviolet-activated powder phosphors. Gallium arsenide is capable of converting electricity directly into coherent light. Gallium readily alloys with most metals, and has been used as a component in low-melting alloys. Here is more information regarding the properties of the element Gallium.
Shown above left is a bar of refined Indium, which weighs approximately a pound. Note the penny providing scale. In the photo above right Kasper demonstrates the softness of Indium by easily slicing it with his knife. Samples of indium were offered at $6 per gram.
Indium is a very soft, silvery-white metal with a brilliant luster. The pure metal gives a high-pitched "cry" when bent. It wets glass, as does gallium. Until 1924, a gram or so constituted the world's supply of this element in isolated form. It is probably about as abundant as silver. Indium is most frequently associated with zinc materials, and it is from these that most commercial indium is now obtained. It is also found in iron, lead, and copper ores. Indium has found application in making low-melting allows; an allow of 24% indium - 76% gallium is liquid at room temperature. It is used in making bearing alloys, germanium transistors, rectifiers, thermistors, and photoconductors. Indium can be plated onto metal and evaporated onto glass, forming a mirror as good as that made with silver but with more resistance to atmospheric corrosion. Here is more information regarding the properties of the element Indium.
Pictured above left are boron samples with a penny providing scale. These were offered at $25 per gram.
Boron is not found free in nature, but occurs as orthoboric acid usually found in certain volcanic spring waters and as borates in boron and colemantie. Ulexite, another boron mineral, is interesting as it is nature's own version of "fiber optics." Important sources of boron are ore rasorite (kernite) and tincal (borax ore). Both of these ores are found in the Mojave Desert. Tincal is the most important source of boron from the Mojave. Extensive borax deposits are also found in Turkey.
Boron of 99.9999% purity has been produced and is available commercially. Optical characteristics include transmitting portions of the infrared. Boron is a poor conductor of electricity at room temperature but a good conductor at high temperature. Boron is used in pyrotechnic flares to provide a distinctive green color, and in rockets as an igniter. Boron pentahydrate is used in very large quantities in the manufacture of insulation fiberglass and sodium perborate bleach. Boric acid is also an important boron compound with major markets in textile products. Use of borax as a mild antiseptic is minor in economical terms. Boron compounds are also extensively used in the manufacture of borosilicate glasses. Other boron compounds show promise in treating arthritis.
An isotope of Boron is used as a control for nuclear reactors, as a shield for nuclear radiation, and in instruments used for detecting neutrons. Boron nitride has remarkable properties and can be used to make a material as hard as diamond. The nitride also behaves like an electrical insulator but conducts heat like a metal. Boron also has lubricating properties similar to graphite. The hydrides are easily oxidized with considerable energy liberation, and have been studied for use as rocket fuels. Demand is increasing for boron filaments, a high-strength, lightweight material chiefly employed for advanced aerospace structures. Boron is similar to carbon in that it has a capacity to form stable covalently bonded molecular networks. Carbonates, metalloboranes, phosphacarboranes, and other families comprise thousands of compounds. Here is more information regarding the properties of the element Boron.
Depicted above right is a rod of refined zirconium which was about 10 inches in overall length. Zirconium samples were offered at $6 per gram.
Zirconium is found in abundance in S-type stars, and has been identified in the sun and meteorites. Analysis of lunar rock samples obtained during the various Apollo missions to the moon show a surprisingly high zirconium oxide content, compared with terrestrial rocks. Naturally occurring zirconium contains five isotopes, with fifteen other isotopes are known to exist. Zircon is the principal ore of Zirconium, which also occurs in some 30 other recognized mineral species. It is a grayish-white lustrous metal. When finely divided, the metal may ignite spontaneously in air, especially at elevated temperatures. The solid metal is much more difficult to ignite. Hafnium is invariably found in zirconium ores, and the separation is difficult.
Zirconium is used for nuclear energy applications, such as for cladding fuel elements. Commercial nuclear power generation now takes more than 90% of zirconium metal production. Reactors of the commercial size, now being made, may use as much as a half-million linear feet of zirconium alloy tubing. Reactor-grade zirconium is essentially free of hafnium. Zirconium is exceptionally resistant to corrosion by many common acids and alkalis, by sea water, and by other agents. Alloyed with zinc, zirconium becomes magnetic at temperatures below 35°K.
Zirconium is used extensively by the chemical industry where corrosive agents are employed. Zirconium is used as a getter in vacuum tubes, as an alloying agent in steel, in surgical appliances, photoflash bulbs, explosive primers, rayon spinnerets and lamp filaments. It is used in poison ivy lotions in the form of the carbonate as it combines with urushiol. With niobium, zirconium is superconductive at low temperatures and is used to make superconductive magnets, which offer hope of direct large-scale generation of electric power. Zirconium oxide (zircon) has a high index of refraction and is used as a gem material. The impure oxide, zirconia, is used for laboratory crucibles that will withstand heat shock, for linings of metallurgical furnaces, and by the glass and ceramic industries as a refractory material. Its use as a refractory material accounts for a large share of all zirconium consumed. Here is more information regarding the properties of the element Zirconium.
Shown above left is an iodine sample, stored in a sealed, argon filled vial. A penny provides scale. These were offered at $25 each.
Iodine is a bluish-black, lustrous solid, volatizing at ordinary temperatures into a blue-violet gas with an irritating odor; it forms compounds with many elements, but is less active than the other halogens, which displace it from iodides. Iodine exhibits some metallic-like properties. It dissolves readily in chloroform, carbon tetrachloride, or carbon disulfide to form beautiful purple solutions. It is only slightly soluble in water. Thirty isotopes are recognized but only one stable isotope is found in nature. The artificial radioisotope 131I, with a half-life of 8 days, has been used in treating the thyroid gland. The most common compounds are the iodides of sodium and potassium and the iodates. Lack of iodine is the cause of goiter.
Iodine compounds are important in organic chemistry and very useful in medicine. Iodides, and thyroxine which contains iodine, are used internally in medicine, and as a solution of KI and iodine in alcohol is used for external wounds. Potassium iodide finds use in photography. The deep blue color with starch solution is characteristic of the free element. Here is more information regarding the properties of the element Iodine.
Shown in the upper portion of the picture above right are Samarium samples with a penny providing scale. The Samarium was offered at $12 per gram.
Samarium is found along with other members of the rare-earth elements in many minerals, including monazite and bastnasite, which are commercial sources. Samarium has not been isolated in relatively pure form until recently. Samarium has a bright silver luster and is reasonably stable in air. Three crystal modifications of samarium exist. The metal ignites in air at about 150°C. The sulfide has excellent high-temperature stability and good thermoelectric efficiencies up to 1100°C. Twenty one isotopes of samarium exist. Natural samarium is a mixture of several isotopes, three of which are unstable with long half-lives.
Samarium, along with other rare earths, is used for carbon-arc lighting for the motion picture industry. SmCo5 has been used in making a new permanent magnet material with the highest resistance to demagnetization of any known material. Samarium oxide has been used in optical glass to absorb the infrared. Samarium is used to dope calcium fluoride crystal for use in optical lasers or lasers. Compounds of the metal act as sensitizers for phosphors excited in the infrared; the oxide exhibits catalytic properties in the dehydration and dehydrogenation of ethyl alcohol. Samarium is used in infrared absorbing glass and as a neutron absorber in nuclear reactors. Here is more information regarding the properties of the element Samarium.
Shown in the lower portion of the picture above right are Dysprosium samples. The Dysprosium was offered at $12 per gram.
Dysprosium occurs along with other so-called rare-earth or lanthanide elements in a variety of minerals such as xenotime, fergusonite, gadolinite, euxenite, polycrase, and blomstrandine. The most important sources are from monaziate and bastnasite. Dysprosium has a metallic, bright silver luster. It is relatively stable in air at room temperature. It is soft enough to be cut with a knife and can be machined without sparking if overheating is avoided. Small amounts of impurities can greatly affect its physical properties.
While not many applications have been found for dysprosium, its neutron absorption and high melting point suggest metallurgical uses in nuclear control applications and for alloying with special stainless steels. A dysprosium oxide-nickel cement has found use in cooling nuclear reactor rods. This cement absorbs neutrons readily without swelling or contracting under prolonged neutron bombardment. In combination with vanadium and other rare earths, dysprosium has been used in making laser materials. Here is more information regarding the properties of the element Dysprosium.
Shown above left are samples of refined halfnium. These were offered at $12 per gram.
Hafnium is a ductile metal with a brilliant silver luster. Its properties are considerably influenced by presence of zirconium impurities. Of all the elements, zirconium and hafnium are two of the most difficult to separate. Although their chemistry is almost identical, the density of zirconium is about half of hafnium. Very pure hafnium has been produced, with zirconium being the major impurity. Hafnium has been successfully alloyed with iron , titanium , niobium , tantalum , and other metals. Hafnium carbide is the most refractory binary composition known, and the nitride is the most refractory of all known metal nitrides.
Hafnium is resistant to concentrated alkalis, but at elevated temperatures reacts with oxygen, nitrogen, carbon, boron, sulfur , and silicon. Because halfnium has a good absorption for neutrons and excellent mechanical properties and is extremely corrosion-resistant, hafnium is used for reactor control rods in nuclear submarines. Hafnium is used in gas-filled and incandescent lamps, and is an efficient getter for scavenging oxygen and nitrogen. Here is more information regarding the properties of the element Halfnium.
Depicted above right is a thumbnail box filled with scandium. A penny provides scale. Samples of scandium were offered at $45 per gram.
Scandium is a silver-white metal which develops a slightly yellowish or pinkish cast upon exposure to air. A relatively soft element, scandium resembles yttrium and the rare-earth metals more than it resembles aluminum or titanium. It is a very light metal and has a much higher melting point than aluminum, making it of interest to designers of spacecraft. Scandium is apparently much more abundant in the sun and certain stars than on Earth. It is widely distributed on earth, occurring in very minute quantities in over 800 mineral species. The blue color of aquamarine is attributed to scandium. It occurs as a principal component in the rare mineral thortveitite. It is also found in the residues remaining after the extraction of tungsten from Zinnwald wolframite, and in wiikite and bazzite.
Most scandium is presently being recovered from thortveitite or is extracted as a by-product from uranium mill tailings. Metallic scandium was first prepared in 1937 with the production of the first pound of 99% pure scandium metal was announced in 1960. About 20 kg of scandium are used yearly in the U.S. to produce high-intensity lights. A radioactive isotope of scandium is used as a tracing agent in refinery crackers for crude oil, etc. Scandium iodide added to mercury vapor lamps produces a highly efficient light source resembling sunlight, which is important for indoor or night-time color TV. Here is more information regarding the properties of the element Scandium.
Depicted above left are samples of refined Terbium with a penny providing scale. Terbium was offered at $18 per gram.
Terbium is a member of the lanthanide or "rare earth" group of elements. It is a silver-gray metal, and is malleable, ductile, and soft enough to be cut with a knife and reasonably stable in air. Two crystal modifications exist. It is found in cerite, gadolinite, and other minerals along with other rare earths. It is recovered commercially from monazite in which it is present to the extent of 0.03%, from xenotime, and from euxenite, a complex oxide containing 1% or more of terbia. Terbium has been isolated only in recent years with the development of ion-exchange techniques for separating the rare-earth elements.
Twenty one isotopes with atomic masses ranging from 145 to 165 are recognized. Sodium terbium borate is used in solid-state devices. The oxide has potential application as an activator for green phosphors used in color TV tubes. It can be used with ZrO2 as a crystal stabilizer of fuel cells which operate at elevated temperature. Few other uses have been found. Here is more information regarding the properties of the element Terbium.
Shown above right are argon filled vials containing samples of europium. These were offered at $55.
Europium is about as hard as lead and is quite ductile. As with other rare-earth metals, except for lanthanum, europium ignites in air at about 150 to 180°C. It is the most reactive of the rare-earth metals, quickly oxidizing in air. It resembles calcium in its reaction with water. Bastnasite and monazite are the principal ores containing europium.
Europium has been identified spectroscopically in the sun and certain stars. Seventeen isotopes are now recognized. Europium isotopes are good neutron absorbers and are being studied for use in nuclear control applications. Europium oxide is now widely used as a phospor activator and europium-activated yttrium vanadate is in commercial use as the red phosphor in color TV tubes. Europium-doped plastic has been used as a laser material. With the development of ion-exchange techniques and special processes, the cost of the metal has been greatly reduced in recent years. Here is more information regarding the properties of the element Europium.
Shown above left is a thumbnail box filled with thulium. Samples of thulium were offered at $45.
Thulium is silver-gray, soft, malleable, and ductile, and can be cut with a knife. It occurs in small quantities along with other rare earths in a number of minerals. It is obtained commercially from monazite, which contains about 0.007% of the element. Thulium is the least abundant of the rare earth elements, but with new sources recently discovered, it is now considered to be about as rare as silver, gold, or cadmium. Twenty five isotopes are known, with atomic masses ranging from 152 to 176. Natural thulium is stable.
Because of the relatively high price of the metal, thulium has not yet found many practical applications. A Thulium isotope bombarded in a nuclear reactor can be used as a radiation source in portable X-ray equipment. Thulium is potentially useful as an energy source. Natural thulium also has possible use in ceramic magnetic materials used in microwave equipment, and can be used for doping fiber lasers. As with other lanthanides, thulium has a low-to-moderate acute toxic rating. It should be handled with care. Here is more information regarding the properties of the element Thulium.
Pictured above right are samples of refined niobium. These were offered at $6 per gram.
Niobium is a shiny, white, soft, and ductile metal, and takes on a bluish cast when exposed to air at room temperatures for a long time. It is found in niobite, niobite-tantalite, parochlore, and euxenite. Large deposits of niobium have been found associated with carbonatites (carbon-silicate rocks), as a constituent of parochlore. Extensive ore reserves are found in Canada, Brazil, Nigeria, Zaire, and in Russia. Niobium starts to oxidize in air at 200°C, and when processed at even moderate temperatures must be placed in a protective atmosphere.
Niobium is used in arc-welding rods for stabilized grades of stainless steel. Thousands of pounds of niobium have been used in advanced air frame systems such as were used in the Gemini space program. The element has superconductive properties; superconductive magnets have been made with Nb-Zr wire, which retains its superconductivity in strong magnetic fields. This type of application offers hope of direct large-scale generation of electric power. Niobium is also commonly used for jewelry. Here is more information regarding the properties of the element Niobium.
In addition to samples of elemental materials Kasper is also showing and offering some interesting rock and mineral specimens. Depicted above left are some samples of KT boundary material from Denmark, with a quarter providing scale. The smaller KT samples were offered at $7 and the larger ones at $30. This layer marks the end of the Mesozoic Era and the dawn of the Cenozoic Era. KT boundary material is distributed around the Earth in various forms and is anomalously high in iridium relative to other terrestrial rocks. The anomalously high iridium content in the KT boundary layer is attributed by many geologists to fallout from the Chicxulub impact 65 million years ago. The Chicxulub impact is also attributed by many paleontologists as the cause of the major extinction event that abruptly took out the dinosaurs, along with the ammonites and many other branches on the tree of Mesozoic life.
Shown above right is a manganese nodule specimen which was collected from the 5000 meter deep sea floor off Southeast Hawaii. According to Kasper, these nodules accrete around shark's teeth although the mechanism of the accretion process is not yet understood. Manganese nodules similar to this one have been discovered in uncountable numbers on deep ocean floors and are ripe as a rich source of manganese for future mining operations. This nodule specimen was offered at $470. Hmm... look like the economics of collecting the nodules from the deep ocean floor are going to have to improve significantly before they become viable as a commercial source of manganese...
Shown above left and right are shungite specimens which is metamorphic rock from the Karelia region of Russia. A quarter provides scale. This material contains naturally formed Buckminsterfullerenes. Up until the 1980s only two forms of carbon were known. The crystalline version, diamond, is the hardest substance known to man. The other form of carbon is graphite, perhaps best known as a major component of pencil lead. In 1985 researchers at Rice University discovered Carbon-60, also known as the Buckminsterfullerene or "Buckyballs".
These shungite specimens wanted from $10 to $180. A closer view of one of the larger shungite specimens at about 3 inches across is depicted above right.
Pictured above left are specimens of polymetallic sulfide bearing rock deposited by deep sea fumaroles, also known as "black smokers". These samples were collected at the Rodrigues Triple Junction in the Indian Ocean. Huge chimneys of this material are deposited as minerals fall out of solution from the superheated water and gasses emanating from these deep sea fumaroles. Unexpectedly rich and complex ecosystems of sunlight independent organisms have evolved in a biosphere dependent on such fumaroles for energy and the basic materials consumed by bacteria at the bottom of their food chains. Ongoing study of these organisms and the ecosystems surrounding black smokers are currently revolutionizing theories regarding the origin of life on Earth as well as where we may find life on other worlds. The black smoker specimens were offered in prices ranging from about $20 for a 1 inch size specimen to $150 for a 4 inch size specimen.
Shown above right are dodecahedral pyrite crystals from Navajun, Spain, with a quarter providing scale. At $3 each one of these is a must have for any fledgling pyrite or general mineral collection needing a specimen displaying the dodecahedral crystal form.
Pictured above left and right are some nice specimens of pyrite "suns" from the coal mines of Sparta, Illinois, with a quarter providing scale. They are found in a narrow seam of shale lying on top of the coal vein which dates back 350 million years and are thought to be pyritized replacements of an undetermined fossil. These suns were wanting from $9 to $22 each, depending on their size and quality, and a sun is another must have form for any fledgling pyrite collection lacking one. The specimen shown in the closer view above right was about 3 inches in diameter and was priced at $18.
GeoFactum, Arizona Mineral and Fossil Show at the Vagabond Plaza Hotel (formerly the Ramada Inn) - WWW: www.geofactum.de Email: firstname.lastname@example.org Kasper von Wuthenau, Diplomgeologe, DorfstraBe 13, 19246 Techin / Germany - Fax: +4940432554061