nlMay2011
The Cochise County Rock
Monthly Newsletter of the Sunsites Gem & Mineral Club
http://sites.google.com/site/cochisecountyrock/
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“Finding and Grinding Rocks in Cochise County, Arizona since 1965”
May 2011
This issue edited by Don Hammer
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The next General Meeting of the Sunsites Gem & Mineral Club is on Monday May 9, 2011 at 7:00 pm at the Sunsites Community Center. Our program will be a video from the series, “How the Earth Works” by Professor Micheal E. Wysession of Washington University. We will resume the “Best Rock” contest so bring your best specimen from the Courtland trip.
General Meeting Minutes April 11, 2011
Diane Dunn called the meeting to order at 7:05 by welcoming new members and visitors.
The Minutes of last month's General Meeting were accepted without comment and without voice vote.
Walter then gave the Treasurer's Report which was accepted as given without voice vote.
Zoe announced that Jane Corley and Sherrie Robb supplied the refreshments for the intermission social time.
Don Hammer asked members to write to the director of the New Mexico Rock Hound State Park to protest the potential closing of the Park to rock hounding.
Henri announced that the April Field Trip would be to the Courtland Mine and to the Gleason Jail.
Before the Intermission, Diane reminded Club members to be "friendly" especially with new comers.
Following intermission and the raffle, Don Hammer gave a fascinating and informative lecture on the history of the Courtland and Gleeson area. Ample historic pictures, using the Club's new projector, along with Don's grasp of the local history revealed the extensive community life of the late 19th and early 20th centuries, propelled by the mining industry, in contrast to the desolation one finds today in driving through the Courtland and Gleeson countrysides. Don's lecture was given in preparation for the upcoming Field Trip to this area.
Respectfully submitted, Jim Brower, Secretary
May Field Trip
We will go to the Dragoon marble quarry for finger agate and dendritic manganese. Meet at 8 am on Saturday May 14 at Lizard Lane (MP 5) on Dragoon Road. High clearance is needed but not 4WD. Much of the finger agate is simply dug out of the dirt so bring light digging tools and knee pads. There is a vein of similar material a bit further up the mountain that requires heavy rock breaking tools. The scaly rock along the west side of the excavation has dendritic manganese. The quarry will likely be in shade early in the morning so dress accordingly. Also bring buckets or bags, drinking and rock washing water, lawn chairs, lunch and sun protection. If we have rain the trip may be postponed or canceled so check your email and the Web site and/or call Diane or Henri.
April Field Trip
On Saturday April 16 27 members and two guests met at the Sunsites Community Center parking lot at 8:15 am and led by Don Hammer, departed at 8:30 am. Don stopped in Central Courtland and pointed out the remains and showed a 1909 photograph that depicted many buildings in the area at that time. We then stopped in South Courtland and examined the few building remnants and compared them with a 1909 photograph. We proceeded to Gleeson where Tina Miller had the Old Jail open and gave us an overview of the history of Gleeson and the Old Jail. The Sigels then led us back to South Courtland and the collecting area. Chrysocolla and malachite were abundant and we found some azurite in rock piles in that vicinity. Everyone had a good collection by noon and Gayle Smullins found a nice piece of white opal.
The Club Library
The Club has an impressive collection of rock and mineral books including field identification guides, guides to collecting areas, lapidary manuals and related topics. If you are interested in checking out any of the books please call Larry Strout (826.3991) or Diane Dunn (826.0278)
Club Website
The address of the Club Website is on the masthead of this newsletter. The Website has past newsletters, photos from almost all of our field trips and other Club information.
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 were dropped on March 31.
Club Calendar:
May
9 General Meeting
14 Field Trip
26 Board Meeting
June
4 Club Picnic
Upcoming Regional Events
May 7
Tucson Gem & Mineral Society Show. 9 am to 4 pm. 3727 E. Blackledge Drive in Tucson. Show@tgms.org or 520.322.5773
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 520.826.0278
V-President: Jack Light 520 824-4774
Secretary: Jim Brower 520 826-4672
Treasurer: Walter Sigel 520-826-1009 Deleg-at-Large: Carl Schnabel520.826.0100
Hospit Coord: Zoe Schnabel 520-826-0100
Field Trip Crd: Henri van den Bos 384-0288
Past Pres: Paul McKnight 775-434-8395
Stone Treatments
Stabilized turquoise is created by adding a clear resin to chalk, or soft, turquoise to help enhance the color and well as increase the hardness of the stone. Chalk, or soft, turquoise is usually a lower grade of turquoise as it is too soft to be used on its own for jewelry and must be stabilized with resin. Since turquoise is a very porous substance, the resin fills in the tiny holes and crevices to form a firm stabilized turquoise stone.
Most turquoise is treated in some way. Natural untreated turquoise is actually quite rare, as only about three percent of the turquoise sold in the world is mined and sold without anything being added to it. The term treated turquoise is used to mean any turquoise that is stabilized with dyed resin rather than clear. Treated turquoise is usually less expensive than either natural or stabilized turquoise, but it may look artificial in color.
Natural turquoise changes color the more it is worn as it reacts with the oils in the skin. Stabilized turquoise, on the other hand, stabilizes, or keeps, the color of the stone the same no matter how much it is worn next to the skin. Stabilized turquoise costs less than natural turquoise, but is still considered beautiful and desirable.
Stabilized turquoise differs greatly from reconsituted turquoise. Reconstituted turquoise is the cheapest type of turquoise. It is a soft, or chalk, turquoise powder that has a great deal of resin and dye added to the powder. This mixture is then pressed into blocks and cut into many different shapes. Imitation turquoise contains no turquoise at all, not even soft, or chalk, turquoise. Either just dyed resin is used to make imitation turquoise or the dyed resin is added to a white stone such as howlite.
It's important for turquoise buyers to know what they're getting since it's not always easy to tell how much resin something sold as turquoise actually contains. One test is to heat a pin and place it on the turquoise. If the stone is actually mostly resin, the pin will sink way into the piece and leave a mark. The turquoise buyer should always get a signed receipt from the seller as to what type of turquoise he/she is supposed to be selling.
Treatments for Turquoise
Stabilized Turquoise
Stablized turquoise has been treated with epoxies or acrylic resins. The chemicals are infused into the turquoise by soaking the material for a long period of time, or by subjecting it to pressure. When stabilized turquoise is cut, there is often a plastic smell. Enhanced Turquoise (Zachary Process)
Enhanced turquoise has been treated with chemicals, then heated. The heating process eliminates any residual chemicals in the turquoise. Therefore, it is difficult to tell the difference between enhanced turquoise and natural, untreated turquoise. Unlike natural turquoise, enhanced turquoise usually does not turn green over time. Natural Processed Turquoise
The Natural Process is a new and exciting enhancement process for turquoise. Natural Processed turquoise has been treated with completely non-toxic chemicals. This process improves the polish and color of turquoise rough, without any dyes or nasty chemicals. If Natural Process turquiose is soaked in water for 24 hours, it is impossible to detect the difference between it and natural, untreated turquoise. Natural Processed turquoise is therefore the least invasive and highest grade of treatment available for turquiose. Unlike natural turquoise, Natural Processed turquoise will not turn green over time. Reconstituted Turquoise
Reconstituted turquoise is natural, or previously stabilized material that has been pulverized into a powder, soaked in binders and then pressed back into a solid block. Reconstituted turquoise cuts easier than stabilized material, but has a lower value. Lapis, coral and other semi-precious gems can also be reconstituted. Block Turquoise
Block turquoise is not turquoise. Instead, it is a simulant made from plastic, ceramic, or other material. Other semi-precious stones, such as malachite, lapis, charoite, etc. are simulated with block materials.
Treatments for Other Stones:
Backed Cabochons
Backed gems have a backing attached to the bottom of the stone. The backing is usually made out of some form of epoxy, or plastic resin. The backing is not seen when the stone is set in jewelry, because only the bottom of the stone has the backing material. Turquoise cabochons are often backed. Heating
Gemstones are often heated to bring out a more desireable color. This does not change the character of the stone and is usually considered an acceptable standard process in the industry.
Irradiation
Some gemstones are irradiated to produce a better color. All commercial blue topaz such as Sky Blue, Swiss Blue and London Blue are irradiated. Sky Blue is usually created in a linear accelerator and very rarely contains any residual radiation. Swiss Blue and London Blue are usually created in a reactor by neutron bombardment. These stones must be tested for residual radiation before they can be legally sold in most countries. The color of irradiated topaz will not fade.
Other stones such as tourmaline, heliodor and scapolite may also be irradiated. Some of these stones may fade after treatment.
Surface Diffusion
Quartz gemstones, especially drusy quartz or drusy agates are surface diffusion treated. The process lays an ultra-thin layer of metal on the surface of the stone. Titanium is the most common metal used, which creates a beautiful rainbow effect on the surface of the stone.
Triplet or Doublet Cabochons
Triplet cabochons have main material in the center that is sandwiched between a backing and then topped with a different cap material. The cap is usually a colorless material such as quartz, glass, epoxy, or synthetic corundum or spinel. Sometimes a colored cap may be used to create a special effect. The backing, or bottom of a triplet is often a dark color to show off the colors in an opal or rutile inclusions in quartz. Backing materials can be dark epoxy, glass, jade, lapis, or any other material. Doublets are the similar to triplets, except they only have two layers. Opal and ammolite are commonly produced as doublets or triplets.