E.S.C.O.N.I.

MINERALOGY-MICROMOUNT STUDY GROUP NOTES 2004

Chairperson: Kathy Dedina

College of DuPage , Bldg. K Room 161 7:30 P.M.

January 10, 2004 "Videos: Gold, Gold Rush"

Meeting was called to order by Kathy Dedina. Two videos from the History Channel Classroom, Gold and The Gold Rush, were shown. They showed the history of gold mining. Originally gold was the property of kings and governments. The various gold rushes in California, Colorado and Alaska involved the individual miner. Now gold mining is done by large companies using destructive techniques such as cyanide processing or high pressure water; both of which devastate the environment.

The books used in the video were:
World of Gold by Timothy Green
Power of Gold by Peter Bernstein

The topic for the February meeting will be gold. The assignments are
Uses of Gold (other than jewelry) - Jim Daly

History - John Good
Property and Coloring – Sheila Bergmann
Geology – Sheila Bergmann

The case for the March Show will be Gypsum. Members are asked to bring in their gypsum specimens to the February meeting so that we pick the ones for the case.

The March Mineral Study Group Meeting will be on Zinc.

MINERALOGY/MICROMOUNT February 14, 2004

Meeting was called to order by Chairman, Kathy Dedina.
John Good had flyers for the March show. He also reported on field trips planned for Spring: Braceville in March, and a new geode locality in Hamilton, IL.
The program for the March meeting will be on sphalerite. John Good will discuss localities and mining. Jim Daly will describe physical properties and crystallography, and Kathy Dedina will report on uses.
The April program will be on identification techniques, and in May we will cover silver and silver minerals.
Specimens were brought to the meeting for the study group’s case in the March show, which will be on gypsum.
This month’s program was on gold.
John Good discussed the history of gold, including these important dates:
4000 BC- First known use of gold in Central and Eastern Europe
3000 BC- Egyptians learn to beat gold into leaf, alloy gold with other metals to vary color and hardness, and cast gold.
1500 BC- Earliest gold coinage, the Shekel
1350 BC- Babylonians use fire assay to test the purity of gold.
600 AD- Byzantine Empire resumes gold mining in Europe for the first time since the fall of the Roman Empire.
1100- Venice becomes the world’s leading gold bullion market.
1511- Spain sends explorers to the Western Hemisphere to “get gold”
1717- Isaac Newton, as Master of the London Mint, sets the price of gold, lasting 200 years.
1787- First US gold coin, the “Brasher Doubloon”
1803- North Carolina gold rush
1848- California gold rush
1850- Discovery of gold in Australia
1859- Comstock Lode in Nevada
1886- Discovery of gold in South Africa
1887- Development of the cyanide process for extracting gold from ore
1896- Discovery of gold in the Klondyke
1927- Use of gold salts to treat arthritis
1968- Price of gold no longer fixed by world banks
1973- US goes off the gold standard

Sheila Bergmann sent in a report on the properties of gold. Gold is the least susceptible native metal to atmospheric corrosion. It has a density of 19.3, and is very malleable. It can be beaten to a thickness of 0.000005”, at which point it is almost transparent and greenish. Gold has an atomic weight of 197.2, a melting point of 1063 C, and a boiling point of 2970 C. It is only soluble in aqua regia, a mixture of 1 part nitric acid and 3 parts hydrochloric acid.

Kathy Dedina described the types of gold deposits, the methods of mining those deposits, and the localities where gold is found.
There are two main types of deposits, placer and lode. Placer deposits are formed by gold freed from the host rock by wind and water, then collecting in places where streams flow or have flowed. The gold can be recovered by panning or sluicing. These are usually simple operations and short-lived. In lode deposits, gold is in seams and veins in the host rock. These deposits are worked by underground mining, with the gold being recovered by leaching with mercury, or more recently with cyanide. These processes are intensive and expensive, but the mines are generally more long-lived. One deposit, the Witwaterstrand in South Africa, is different from these two types. It was originally formed as a placer deposit, but the gold-bearing silt was later compacted into a conglomerate, so it has to be mined by lode methods. Some gold is also obtained as a by-product of copper and lead mining.
Gold is found almost everywhere. The earliest mining locality was Egypt. Other areas include the US, South Africa, Australia, Venezuela, Canada, Brazil, the Philippines,
Russia, Papua-New Guinea, and Mexico.

Jim Daly outlined some of the uses for gold other than jewelry, which consumes about 90% of the gold mined:
MONETARY USES
Gold was for many centuries the primary international medium of exchange. At first, countries used gold coins, but later kept most of their gold in depositories, such as Fort Knox or the Federal Reserve in New York, issuing paper money backed by the gold they held. Since 1933, US currency has not been backed by gold.
DECORATIVE USES
Gold can be beaten to a very thin film called gold leaf. This has been used to gild ornate picture frames, for lettering on glass windows, and for the background on some paintings in the Middle Ages. It can also be used on buildings, such as the “golden dome” at the University of Notre Dame in Indiana.
Gold has also been used for tableware instead of silver, and to gild fine china.
DENTISTRY
Gold is used extensively for crowns and prostheses because it is extremely inert to corrosion or other chemical reaction.
PHOTOGRAPHY
In traditional chemical photography, chlorauric acid, HAuCl4, is used to tone the silver image.
ELECTRONICS AND TELECOMMUNICATIONS
Gold is used in printed circuit boards and in the wire connecting the circuits to semiconductors because of its excellent conductivity and resistance to corrosion. These circuit boards are found everywhere, from TVs to spacecraft to computers.
Gold is used in an instrument designed to detect and monitor ionizing radiation in spacecraft. It is also an integral part of the instrument used on the Mars Rover to analyze soil and rocks.
There is a gold-plated dome in the diaphragm in the mouthpiece of every telephone. Gold also coats the contacts in telephone wall jacks.
LASERS AND OPTICS
Telescopes with mirrors coated with gold can detect infrared radiation (heat) from very distant stars because of gold’s excellent reflectivity of infrared light.
Copy machines also use gold-coated mirrors to reflect the heat used to produce images.
The CDs used by Kodak in their Photo CD System use gold in their reflective surface.
Electronic circuitry boxes in satellites are gold coated to protect the electronic devices from cosmic rays.
Gold-coated Mylar sheets are wrapped around the main body of satellites to reflect away solar heat.
Nighttime security cameras have gold in their consruction to enable them to “see” infrared light.
MEDICINE AND HEALTH
Gold eyelid implants are used to treat a medical condition in which the eyelid cannot close fully. The weight of the gold helps the eyelid close.
Gold vapor lasers are used to destroy cancer cells without damaging nearby healthy cells. Gold lasers are also used by medical corpsmen to seal battlefield wounds in the field. They are also used to clear clogged coronary arteries.
Radioactive gold isotopes are also used for cancer treatment because they are chemically inert and have a short half-life (2.694 days for Au-198).
Disodium aurothiomalate is used in the treatment of rheumatoid arthritis.
Gold is a key component in modern digital thermometers. They contain a gold-coated tube that acts as a “waveguide”.
INDUSTRY AND AVIATION
Gold-plated contacts are used in automobile airbag deployment systems.
Gold is a major constituent of a brazing alloy used in the manufacture of stator and tube assemblies for aircraft engines.
Many aircraft cockpit window defrosters use gold-coated acrylic. During hot weather, the gold coating reflects away heat on hot runways, and at high altitudes it helps retain heat in the cabin.
The face plates of the protective gear worn by firefighters has a gold coating to protect the firefighters eyes from heat and infrared radiation, while allowing him to see clearly.
Gold-coated sensors are used in the food industry to measure levels of carbon dioxide, which is used to prevent spoilage of fruits and vegetables.
Air Force One, the President’s airplane, is equipped with gold-plated reflectors that confuse the heat-seeking sensors of missiles.

Frank provided refreshments.
Submitted by Jim Daly, Recording Secretary

MINERALOGY/MICROMOUNT March 13, 2004

Meeting was called to order by Chairman, Kathy Dedina.
Dave Bergmann brought “freebies” of micro sphalerite crystals from Millersville, OH and Jim Daly brought “freebies” of sphalerite from Linden, WI.
The April meeting will be on identification techniques. Jim Daly will give an overview of methods and techniques. John Good will describe the physical properties of minerals useful for identification, Kathy Dedina will present a listing of sources for identification data, Sheila Bergmann will discuss the associations between mineral species, and Jim Daly will describe chemical and instrumental tests and analytical techniques. All members are requested to bring specimens illustrating properties such as luster.
This month’s program was on sphalerite.
John Good presented information on localities and mining techniques, using COD’s new audiovisual equipment that accesses the internet and projects web pages on the screen.
The Tri-state (MO/KS/OK) region was the best-known zinc mining area in the US that mined sphalerite. Mining started in 1838, and peaked in 1918-1941. Mainly lead was mined until 1869, but zinc predominated after that. The last mine, near Baxter Springs, KS, shut down in 1970. Over the history of the district 4000 mines produced 23 million tons of zinc concentrate. Most of the mines were underground, using the room and pillar method. Walls of the rooms were 25-100 feet high, and pillars were 20-50 feet thick. There were also some surface mines near Galena, KS, where the deposits were closer to the surface.
The Tara Lead-Zinc Mine, Navan, County Meath, Ireland is probably the worrld’s largest lead-zinc mine. In 2000 it produced 152 million tons of zinc concentrate. It uses underground trackless mining techniques, which are highly automated.. Primary cruching is underground, with final crushing and flotation separation taking place on the surface. All process water is recycled.

Jim Daly described the physical properties and crystallography of sphalerite:

PHYSICAL PROPERTIES

Hardness 3.5- 4
Specific Gravity 3.9- 4.1
Refractive Index 2.370- 2.428 (high)
Luster resinous to adamantine
Cleavage dodecahedral (4 cleavage planes), one perfect
Color commonly yellow, brown or black. Almost colorless when pure. It can also be red, green or white.
Streak pale brown to colorless
Some varieties phosphoresce when scratched
Most important distinguishing properties are the cleavage and luster.

CHEMICAL PROPERTIES

Soluble in hydrochloric acid with evolution of hydrogen sulfide (rotten egg smell)
Difficult to fuse. In a blowpipe flame on charcoal leaves a yellow coating (zinc oxide) which turns white on cooling.

CRYSTALLOGRAPHY

Sphalerite crystallizes in the isometric system (3 axes, all the same length, all at right angles to one another), tetrahedral class. Atomic structure is similar to that of diamond.
It forms primarily tetrahedrons, sometimes both the positive and negative tetrahedrons on the same crystal. The two forms have slightly different luster and etch lines. Cube, dodecahedron and tristetrahedron faces are also possible, and twins are common.

Kathy Dedina provided refreshments.
Submitted by Jim Daly, Recording Secretary

MINERALOGY/MICROMOUNT April 10, 2004

Meeting was called to order by Chairman, Kathy Dedina.

John Good discussed upcoming field trips. On April 25 we will go to Lonestar for fossils. The trip to Keokuk for geodes was cut short due to bad weather. It will be rescheduled in June. In May, we are trying to get in to Illinois Cement one last time before it closes. Another trip to Braceville will also be scheduled.

The Chicagoland Show, May 29 & 30 at the DuPage County Fairgrounds, was announced.

Next month’s program will be on silver. John Good will discuss it’s history. Jim Daly will describe its physical properties, crystallography and uses. Phil Smith will report on localities for silver. Kathy Dedina will talk about mining techniques used.

PHYSICAL PROPERTIES

Color is perhaps the most obvious property of a mineral, but may be one of the least useful, because of the variability of color in many minerals. Only use it if you know the colors of the minerals from the specific locality you are dealing with. Of much more use is streak, which is actually the color of the powdered mineral, and a constant for the species.

Bob's RockShop Mineral Identification Key

CHEMICAL TESTING

Chemical tests can be grouped in categories: spot tests, closed tube and open tube tests, blowpipe tests, flame tests, qualitative analysis, quantitative analysis, and instrumental analysis.

Spot tests are tests done with liquid reagents. The most convenient way to do them is on a spot test plate. A small sample of the mineral, preferably powdered, is placed in one of the depressions in the plate, and the reagent added from an eyedropper. The reaction is then observed. Lewis gives a listing of such tests and reagents. Most of these tests are impractical, since a large number of reagents would have to be kept on hand. Of course, the simplest test, using hydrochloric acid to test for carbonates, is quite practical.

Closed and open tube tests involve heat. Small fragments of the mineral are placed in a glass tube, and the tube is heated in the flame of a Bunsen burner. The closed tube is closed at the bottom, so that little air gets to the sample. It is heated at the closed end, with the tube held horizontally, so the open end stays cool. The idea is to collect any sublimate. The open tube, on the other hand, is open at both ends and bent in the middle. It is heated vertically, so as to get a draft of air to oxidize the sample. Lewis has tables with the interpretation of the results.

Blowpipe tests are done on a block of charcoal or plaster. A small hollow is made in the block to hold the sample, and it is then heated by directing a flame onto it with a blowpipe. Tests can be done with either a reducing (blue) or an oxidizing (yellow) flame. The source can be a Bunsen burner, a butane torch or even a candle. Some of the observations to be made are color of sublimate (both hot & cold) odor and flame color. In some cases, a chemical spot test can be made on the sublimate. Again, Lewis describes the procedures and the interpretation of the results.

Flame tests can be done by holding the specimen directly in the flame (with tweezers), or by making a bead of borax or sodium metaphosphate in a loop in a platinum wire. The bead is then heated, touched to the sample, and reheated. The color imparted to the flame and the color of the bead are noted. When the sample is heated directly, fusibility is also noted.

Qualitative analysis is a procedure to determine all the elements present in a sample by a systematic procedure of solution and precipitation. It is very time-consuming, and probably not indicated unless you have no idea about the sample. Most of the other tests will give sufficient clues to enable an identification. Quantitative analysis is the determination of the exact amounts of the elements in the specimen. Again, in most cases it’s probably more trouble than it’s worth.

INSTRUMENTAL ANALYSIS

Most of the techniques described have been replaced by instrumental methods that are much faster and require less in the way of technique. Their only drawback is cost. The instruments used are way out of reach for most of us. The only exception is the flame spectrometer, which can be made at home for practically nothing. It is a shoebox with a thin slit. A diffraction grating or prism would also work. Essentially, all you need is a flame source, such as a butane torch, a means of breaking the emitted light down to a rainbow, and a place to project it. Calibration would be the main problem. A commercial one can be purchased for $ 7.95 from Science Kit (www.sciencekit.com)

We all know how various elements will color a flame. All the spectrograph does is separate the colors caused by each element present by wavelength. The wavelength identifies the element, and the intensity (brightness) of the line indicates its concentration.

Today, most analyses of minerals are done by EDX. This stands for Energy-Dispersive X-ray. It’s an attachment to a scanning electron microscope (SEM). The SEM is used to pinpoint the exact location on the sample that you wish to analyze, then that spot is bombarded with X-rays. These excite the atoms to a higher energy state, much as a flame or UV light does. When the atoms return to their normal state, energy is given off. The wavelength of the energy is characteristic of the element, and its intensity is a measure of the amount present. There is software available to convert this raw data into a list of elements present by percent, or even generate a chemical formula.

REFERENCE TEXTS

English, George, Getting Acquainted With Minerals

Kraus, E.H., Hunt, W.F. an Ramsdell, L.S., Mineralogy, McGraw-Hill, 1951

Dana, E.S. and Ford, W.E., A Textbook of Mineralogy, Wiley, 1932

Lewis, J.V., A Manual of Determinative Mineralogy, Wiley, 1921

Smith, O.C., Identification and Qualitative Chemical Analysis of Minerals, Van Nostrand

www.rockhounds.com

www.mindat.org

ASSOCIATIONS

Often the other minerals associated with an unknown mineral can provide a clue to it’s identity. The Audubon Society Field Guide to North American Rocks and Minerals provides a lot of useful information regarding associations.

Sheila Bergmann provided refreshments. Submitted by Jim Daly, Recording Secretary

MINERALOGY/MICROMOUNT May 8, 2004

Meeting was called to order by Chairman, Kathy Dedina.

John Good discussed upcoming field trips. Illinois Cement Quarry is no longer available. It is closed and flooding. Another trip to Braceville will be scheduled.

The Chicagoland Show, May 29 & 30 at the DuPage County Fairgrounds, was announced.

Jim Daly reported on additional information on mineral identification. Rocks and Minerals has an article explaining Energy Dispersive X-ray (EDX) analysis. Jim has purchased a spectroscope from Boreal. The scale is quite small making it difficult to read to much better than 100 Angstroms. In addition, samples would in most cases have to be in solution. All in all, it could be useful for confirmation of the presence of a specific element, but wouldn’t be of much use for a complete analysis.

There was discussion of the purchase of a Geiger counter for the group. John Good will research the availability and pricing of used units on E-bay, etc.

Future programs were determined. In June we will study sulfur. September will be a video. In October we will discuss fake mineral specimens. In November we will cover the native elements that have not been the subject of programs of their own. Jim Daly will have a list next month. December will be the infamous identification contest.

This month’s program was on silver.

HISTORY (John Good)

PROPERTIES (Jim Daly)

PHYSICAL PROPERTIES

Cleavage: None

Fracture: Hackly. Ductile and malleable.

Hardness: 2.5 to 3

Specific Gravity: 10.1 to 11.1. Average 10.5. The variation has two causes: Admixture of other metals, such as copper, platinum antimony, bismuth, mercury or gold, and other polytypes. Silver 3-C, the most common polytype, is 10.5. Silver 2-H is 10.11, and silver 4-H is 9.53.

Luster: Metallic

Color and streak: Silver-white. Often tarnishes gray to black.

Conductivity: An excellent conductor of heat and electricity.

CHEMICAL PROPERTIES

Fuses before the blowpipe on charcoal to a silver-white globule. In the oxidizing flame forms a faint dark red coating of silver oxide. Crystallizes on cooling.

Soluble in nitric acid. Is redeposited on a copper plate.

Precipitated from solution by hydrochloric acid as white, curdy silver chloride.

CRYSTALLOGRAPHY

Silver 3-C crystallizes in the isometric system, hexoctahedral class. This is the polytype we will discuss. The 2-H and 4-H polytypes crystallize in the hexagonal system, but are quite rare.

The most common crystal form is the octahedron, followed by the cube. The crystals can also be extremely elongated into wire.

Goldschmidt has 4 pages of drawings of silver crystals.

USES (Jim Daly)

Sterling silver for jewelry and silverware

Photography (as AgBr)

Coinage

Dental alloys (amalgam, braces, etc.)

Soldering and brazing

Electrical contacts

Batteries

Printed circuits

Mirrors and coatings (including thin invisible films on glass)

Catalysis of chemical reactions

Seeding of clouds (to make rain)

Bactericide (medical, water purification and plastics)

Solar energy (photocells for solar electricity, reflectors for solar heat)

MINING (Kathy Dedina)

Much less is known of the mining and refining techniques used for silver than is known for gold, for example. While native silver is still mined in Mexico, and a few other locations, much of the silver produced today is as a by-product of lead/zinc or copper mining. In addition, 30% is from recycled, rather than mined, silver. Refining methods would vary greatly, depending on the type of ore mined. For example, the Red Dog Mine in Alaska sends 0ne-third of it’s concentrate to British Columbia for refining, one-third to Europe and one-third to the Far East. This may be due to different refning equipment being available in each of these areas.

LOCALITIES (Phil Smith)

The table shows a list of mines producing silver in the US at this time. There is no distinction between native silver, other silver minerals such as sulfides or tellurides, or production as a by-product of the mining of another metal

Refreshments were provided by Frank Pranshke and Sheila Bergmann

Submitted by Jim Daly

MINERALOGY/MICROMOUNT June 12, 2004

Meeting was called to order by Chairman, Kathy Dedina.
Randy Bultman discussed upcoming field trips. Illinois Cement Quarry is scheduled for June 27. Hopefully they will have pumped out the area where we would be going by then. Another trip to Hamilton, IL for geodes will be scheduled for July 17. The previous trip was cancelled due to bad weather. Phil Smith went anyway, and got some good material.
The Lawrence County, Indiana Show, June 25-27 at the Monroe County, Indiana Fairgrounds, was announced.
Jim Daly announced that a revised version of Heinrich’s Mineralogy of Michigan has been published.
Dorothy Auler announced that she will be moving, and will be selling her remaining fossils, etc. during the summer.
John Good announced that the contents of the ESCONI shed would have to be moved to a new location soon.
Discussion of the purchase of a Geiger counter for the group was tabled until Fall. John Good will research the availability and pricing of used units on E-bay, etc. Now that he has the model number of the unit we are interested in, he can get comparative pricing.
Future programs were determined. September will be a video. In October we will discuss fake mineral specimens. In November we will cover the native elements that have not been the subject of programs of their own. Jim Daly distributed a list of native elements to be used in making assignments in September. December will be the infamous identification contest.
This month’s program was on sulfur.
John Good spoke of the history of sulfur production and use. While there is record of sulfur being used as early as 2000 BC, no sulfur is mined today. This is because enough sulfur is generated as byproducts of other processes to satisfy the world’s demand. Total production and use is 50 million metric tons per year worldwide.
Jim Daly described the properties and crystallography of sulfur.
Sheila Bergmann described the localities where sulfur is found. Most deposits are either sedimentary evaporite types or volcanic, around fumaroles of volcanos. The most important economic deposits are off the coast of Louisiana and Texas, but they produce no specimens. They are mined by the Frasch process, where the sulfur is melted and pumped to the surface in the liquid state. The best specimens come from mines in Italy. Other localities for good crystals are Baja California, Mexico; Bex, Switzerland; Malvesi, France; Cadiz, Spain; and Michigan, USA.
Kathy Dedina listed some uses for sulfur. 90% of all sulfur is used to produce sulfuric acid. This is then used to make a host of other chemicals, including hydrochloric and nitric acids. 70% of all sulfuric acid is used in the manufacture of fertilizers. Sulfur is also used in the vulcanization of rubber. As sulfites, it is used to bleach paper, and as a preservative. Sulfites are no longer used to preserve produce because of allergic reactions in some people. All in all, sulfur is used in about 30,000 different items, including everything from pharmaceuticals to gunpowder.

Refreshments were provided by Kathy Dedina
Submitted by Jim Daly

MINERALOGY/MICROMOUNT September 11, 2004

Meeting was called to order by Chairman, Kathy Dedina.
John Good announced an upcoming field trip to St. Paul, IN on September 18. He also mentioned that there might be a problem with the date for our March show.
Jim O’Brien requested information on collecting localities in NY, NJ and New England, since he will be making a trip there in a few weeks.
The Lawrence County, Indiana Show was held on June 25-27 at the Monroe County, Indiana Fairgrounds. Jim Daly showed some pictures from the show, which was attended by himself and Dave and Sheila Bergmann.
Jim Daly brought a copy of the revised version of Heinrich’s Mineralogy of Michigan, which has been published recently.
Assignments were made for October’s program on fake mineral specimens:
Kathy Dedina will discuss color enhancement.
John Good will discuss fraudulent labeling of specimens.
Jim Daly will report on artificially grown crystals.
John Good will also report on the gluing of loose crystals onto matrix, and other “repairs”.
In November we will cover the native elements that have not been the subject of programs of their own. December will be the infamous identification contest.
In place of a video, this month’s program was the viewing of mineral photos on the website of the St. Marie-aux-Mines (France) Show, www.minerapole.com. These were photos of specimens from the collections of many advanced collectors, taken by some of the best mineral photographers. Surprisingly, though, there were no photos by our own Dan Behnke. The pictures were really spectacular when seen on COD’s projection system.
Submitted by Jim Daly

MINERALOGY/MICROMOUNT Mineral Fakes (October 2004)

Any specimen that is not 100% natural in origin is a fake. That is not to say that it is necessarily fraudulent. If a specimen is labeled to show exactly what it is, the buyer can decide whether they consider it to be collectible or not. Many collectors will collect “minerals” formed in slag, for example. The slag minerals from Laurium, Greece, in particular, have been considered exceptions. Some less legitimate but beautiful specimens are the zincite crystals from a smelter in Poland. Algodonite from Tsumeb is also thought to have been created in a smelter [1].
Another gray area is minerals that form as a result of a mine fire, or other post-mining condition. The reasoning here is that even if the fire wasn’t started by a human, if there wasn’t a mine, there wouldn’t have been a fire. Good examples of these types of “minerals” are the lead carbonates from the Tonopah-Belmont mine in Arizona and the “minerals” formed around the fumaroles of burning coal mines in Pennsylvania.
A fake mineral isn’t even always intentionally created. There was a report [2] of a specimen of copper that had crystals of copper acetate hydrate on it. Copper acetate hydrate isn’t known as a mineral species. It is suspected to have formed as a result of cleaning the specimen (in acetic acid).
Among the deliberate fakes are crystals grown in the laboratory, usually onto a piece of matrix. Such fakes have been around for a long time. The Mineral Collector, vol. 4, p. 10 (1897) mentions a method of preparing hematite artificially, which was developed by a Mr. H. Arctowski. W. S. Valiant of Rutgers University in 1910 referred to “meteorites made in a blacksmith shop”.
The easiest crystals to grow artificially [3], of course, are those of water-soluble minerals. The most common is chalcanthite, followed by halite. Others that have been faked are morenosite, lopezite and potash alum.
In the mid-1970s Dr. Sergio Martinat grew spectacular sulfur crystals on authentic matrix from the Sicilian sulfur mines [4]. These went undetected for many years, until he revealed what he had done. They can only be detected with triethyl phosphine, which gives a red precipitate in the presence of carbon disulfide, the solvent used to grow the crystals.
Gold has been precipitated from a solution of a gold salt onto quartz or pyrite.
Because of their low solubility, more crystals have been grown from melt than from solution. These include quartz (particularly amethyst), copper, gold, bismuth, moissanite, silver, antimony, nickel, corundum and zincite.
Turquoise has also been synthesized in the laboratory [5].
Urea, another compound not found as a natural mineral, has been grown on matrix and sold as aragonite [6].
Edwards [7] describes a method, first published in 1919 in Germany, of growing wire silver and acanthite crystals from silver beads and a sulfide.
As one might expect from its value, gold specimens are frequently faked. Molten gold has been dripped onto rhodochrosite from Colorado and dolomite from the Morro Velho Mine, Brazil. Copper crystals have also been electroplated with gold. Gold crystals from Venezuela in 1991 are suspected of being cast from molten gold [8].
Copper has been made to crystallize out of aqueous solution into the voids and grain boundaries of cryptocrystalline quartz by means of a laser [9].
Bornite has been faked by boiling chalcopyrite in bleach to generate an iridescent film on the surface [10].
Blue pyrrhotite was produced in Brazil by soaking in an alkaline solution containing copper [11]

[1] Mineralogical Record 13; 145
[2] Dunn, P., Mineralogical Record 12; 49
[3] Dunn, P., et.al., Mineralogical Record 12; 210
[4] Pagano, R., Mineralogical Record 33; 149
[5] www.americana.net/tourq.html
[6] Dietrich, M. and Dietrich, R., Gems and Minerals 29-30 (1967)
[7] Edwards, D., Mineralogical Record 32; 72 (2001)
[8] Mineralogical Record 22; 53
[9] Mineralogical Record 12; 212
[10] Mineralogical Record 12; 213
[11] Mineralogical Record 17; 145

MINERALOGY/MICROMOUNT November 13, 2004

Meeting was called to order by Chairman, Kathy Dedina.

John Good announced an upcoming field trip to Lone Star Cement on November 21. He also discussed a problem with the March show. We will not be able to set up on Friday evening, and will have to do so at 7 AM on Saturday. Saturday show hours will therefore be 11 to 6.

We also discussed the possibility of moving our April meeting to the third Saturday, to avoid a conflict with MAPS.

All study group officers were reelected for another year.

The December meeting will be the Identification Contest. Bring 3 unlabelled specimens and 4 specimen names on pieces of paper (the 3 correct identifications and one “red herring”)

The January program will be a video on the Sweet Home Mine in Colorado. February is yet to be determined. In March we will study the minerals of China.

This month’s program was on the native elements that we haven’t discussed previously.

Sheila Bergmann presented data on Arsenic. Arsenic is not common as a native element. It is more commonly found as a sulfide, such as realgar or orpiment, or mixed with silver ores. It is tin-white and metallic, but tarnishes. Crystals, which are uncommon, are rhombs, resembling cubes.

Kathy Dedina discussed Mercury. Mercury has no crystal structure a room temperature, since it is a liquid. It is usually found as balls on mercury ores, such as cinnabar or calomel. It has a high specific gravity: 13.5. A major use today for mercury is in the manufacture of chlorine and caustic. Past uses have been in thermometers, in dentistry as amalgams with gold or silver, and in the extraction of precious metals from their ores. The main localities are Almaden, Spain and Sonoma Co., California.

Kathy also discussed the Platinum group of metals: Platinum, Palladium, Rhodium, Ruthenium, Osmium and Iridium. Platinum and Palladium are the best known of these. Both are found primarily as fine grains. Crystals are rare, but cubic. Both are ductile and malleable, are tin-white, with a shiny gray streak. Platinum is much heavier, with a specific gravity of 21.4, versus 12 for Palladium. Both are used as automotive exhaust catalysts, palladium for gasoline engines, platinum for diesel. Platinum is also used in fuel cells, in jewelry, and electronics. Most platinum comes from South Africa, while palladium is primarily found in Russia.

John Good gave some information on Rhodium and Silicon. Rhodium is similar to Platinum and Palladium, and usually occurs with them. It’s most common use is as an alloying agent with Platinum or Palladium. Silicon, while one of the most abundant elements on earth (silica, quartz, sand) is extremely rare as a native element. It has been found at 3 localities in Russia, one in Tibet, one in Cuba, and one in Oregon. It is iron-black or red-brown, with a metallic luster, black streak and a hardness of 7.

Sheila Bergmann spoke of Tellurium, another semi-metal, like Silicon, Selenium and Sulfur. It is also quite rare as a native element, being found in only a few localities in Romania, Australia and Mexico. It crystallizes in the hexagonal system, but is normally found uncrystallized, with Iron, Gold and Sulfur mixed in.

There are still a few native elements we have not discussed: Aluminum, Antimony, Bismuth, Cadmium, Chromium, Indium, Iridium/Osmium/Ruthenium (always found together as a mixture), Iron, Lead, Nickel, Rhenium, Selenium, Tin and Zinc.

Refreshments were provided by Dorothy Auler.

Submitted by Jim Daly

MINERALOGY/MICROMOUNT December 11, 2004

Meeting was called to order by Chairman, Kathy Dedina.

John Good discussed a problem with the March show. We will not be able to set up on Friday evening, and will have to do so at 7 AM on Saturday. Saturday show hours will therefore be 11 to 6.

We decided to move our April meeting to the third Saturday, to avoid a conflict with MAPS.

The January program will be a video on the Sweet Home Mine in Colorado. February will be on the native elements Iron, Nickel, Bismuth and Lead. In March we will study the minerals of China.

This month’s program was the identification contest. There was a tie for first place between Sheila and Dave Bergmann, who each had 17 correct out of 20.

Refreshments were provided by Sheila Bergmann, Kathy Dedina and Jean Reynolds.

Submitted by Jim Daly

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