No Stone Unturned
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No Stone Unturned Club Rooms: Youth Centre Grounds, Opening Times: Editor & Publisher: 129 Mulgrave Rd. Cairns, Queens- News and views of the Monday: 7:00pm-9:30pm Wednes- Jeanne Mora land. PO Box 389, Westcourt day: 8:30-4:00pm (7:00pm-9:30pm Cairns Mineral & Lapidary Queensland 4870 tuition) Saturday: 10:ooam-4:00pm Phone: 07 4033 0028 Club Inc is for…..OCTOBER and OPALS (October’s birthstone and Australia’s famous gemstone) The opal fields are in the area of a long-gone, shallow, inland sea which varied in size over the eons, at one time splitting the land mass of Australia into several large islands before finally drying up altogether. In the process of drying up the salts formed, in plac- es, the wonderful gemstones, opals, in a process that is still not well understood. There are still remnants of this sea visible today, including the great inland salt lakes, the largest of which are Lake Eyre, Lake Torrens and Lake Frome. The shallow waters of the Gulf of Carpenteria were part of the sea and the invisible Great Artesian Basin lies under the area where waves once lapped. This sea was populated by a plethora of marine species large and small, including pliosaurs, mosasaurs, plesio- saurs, and ichthyosaurs all of which were closer related to reptiles to the better known land-dwelling dinosaurs of the Cretaceous period. Although Australia seems to have less dinosaur fossils than many other countries, (because a fair amount of the continent was under water), from time to time, some stunning fossilized marine creatures are found and painstakingly reconstructed by museum personnel. Two such finds are Chillagoe’s, “ Dave” and Coober Pedy’s , “Eric”. Meet them both in this issue. CHILLAGOE CELEBRATES “DAVE” The people of Chillagoe have erected a statue of “Dave”, the plesiosaur., of the type called an elasmosaurid. Dave (or his fossilized bones) was encased in sandstone near the bottom of a creek bed about 60 km from Chillagoe. The find, dubbed the “find of the decade”, comprised 80% of the plesiosaur’s skele- ton (see illustration below). The creature had four flippers and resembled a seal with a very long neck (see illustration left). This information was found on the websites: http://www.qld.gov.au. More about Dave on page 8. October 2009 Issue How Safe are Your Work Practices? 1 OFFICE BEARERS INSTRUCTION CLASSES CLUB PATRON HON DESLEY BOYLE MP Dates will be advertised on notice board.. President Bill Reece Ph 4054 2498 Cabbing $30:00 (includes material) Vice President Allan Rose Ph 4039 3880 Secretary Jeanne Mora Ph 4033 0028 Jewellery $80:00 (includes material) Treasurer Anne Barham Faceting $60:00 (includes material) Assistant Secretary David Croft Casting $5:00 per flask Assistant Treasurer Jan Saal (You must purchase all materials for casting. Please see Bill Hall to order OTHER PERSONNEL commercial waxes, which take up to three weeks to arrive. Investment Purchasers Betty Reece, Bill Hall, Spec- powder, wax & silver are all available for purchase at the counter. imen Curators David Croft, Laurel Voigt WORKROOM FEES (payable at counter before sessions) Cabochon Instructors Kevin Voigt, Chrissy Wilson Silver Instructors Jenni Hedges, Sylvia Rose, Monday Night : $4:00 Jan Saal, Bill Hall. Wednesday: Full day: $8:00 Faceting Advisor Jim Lidstone, Noel Hedges, Joe Ferk, Trevor Hannam Half Day: $4:00 Carving Advisors Jean Morrow Saturday : Full day: $6:00 Machinery Curators David Croft, Jim Lidstone Half Day: $4:00 (Meeting Satur- Specimen Testers David Croft, Trevor Hannam days, no work is to be done while meeting is in progress) QLACCA Delegate Bill Reece CUTTING FEES Youth Centre Delegate Bill Reece 30c / inch² (members) Librarians Betty Reece, Jean Morrow Events Coordinators Noel Hedges, Allan Rose 50c / inch² (non-members) Honorary Auditor Vic Cummings The positions of Field Officers and carving advisors are yet to be A very warm welcome to our new members: filled Chelse Crockford, Scott Jacobi, Oliver Brinkman Please give these people all the help you can! MEETINGS General Meetings are held at 1:00pm on the first Saturday of each month. (unless otherwise advised) Management Committee Meet- October Birthdays: ings held at 10:30am last Saturday of the month (unless advised otherwise) Jeanne Mora, Peter Moore, Kevin Voigt, Kyle Blackshaw, CLUB HOURS Anne Barham, Debbie Davie, Leon Dornonville, Lynda Hensher, Dennis Kable, Renee Melville, Jake Melville, Jennifer Shephard, James Spencer. Monday Nights: 7:00pm to 9:30pm Wednesday; 8:30am to 4:00pm Wednesday Night: 7:00pm to 9:30pm (Classes) President Bill & wife Betty are holidaying, so there is no Saturday: 10:00 am to 4:00 pm President’s report on page 3. We hope they have an Club closed on long weekends and public holidays. enjoyable time. MEMBERSHIP FEES (due January 1st) Family: New $54:00 / year Family: Renewal $34:00 / year Well I didn’t Know That! Single Member: New $27:00 / year One of the most fascinating things about lapidary, is that you can Single Member: Renewal $17:00 / year always learn something new about the hobby. Almost every time I talk to a member, I pick up a snippet of information that I’ve never (Members are those over 12 years of age. Children under the age of 12 are heard before (or heard and forgotten). I’ll bet you have too! Lets start welcome on field trips and in the main Clubroom under their parents’ supervi- passing these tips on to all members. Please let me know of any you sion. (They must not enter the workrooms.) hear for future publications. Editor The Editor wishes to advise that articles or advertisements for Trash or Treasure? inclusion in “No Stone Unturned” should be handed to the editor or emailed. All articles must be signed and will be pub- lished at the Editor’s discretion. The Editor reserves the right Advertise any lapidary gear you don’t want in “No Stone to emend all copy used. Contributions should be submitted 2 Unturned”. Someone may be needing what you can no longer weeks before the monthly meeting. use. Ads are free for members. Opinions expressed in articles are not necessarily those of the Club or the Editor. The Publisher is not responsible for any consequence of inaccuracy or omission. The Publisher excludes all warranties able by law to be excluded. October 2009 Issue How Safe are Your Work Practices? 2 COMMON FACETING GEMSTONES & THEIR PROPERTIES Corundum: Aluminium Oxide Chemical Formula: AL2O3 • Colour: Mostly Blue, Yellow, Green, Pink, Colourless, Purple and Bi colours Red - Deep Red to a dark Pink with a Hue of Violet • Transparency: Crystal Clear to Translucent • Hardness: 9 • Streak: White • Cleavage: None • Fracture: Conchoidal type fracture, Splintery • Crystal Structure: Hexagonal (Trigonal) • Specific Gravity: 3.17 to 3.23 • Refractive Index: 1.766 to 1.774 • Dispersion: 0.008 • Pleochroism: Definitely Dichroic - Darker colours usually show stronger dichroism. Natural blue: distinct (dark blue to greenish-blue); Natural green: weak (more or less yellow); Natural orange: strong (orange to yellow-brown or colourless); Natural purple: distinct (purple to pinkish); Natural ruby: strong (deep red to yellowish-red); Natural yellow: weak (yellow to light-yellow). • Birefringence: Double Refractive - Weak to Medium (.018) • Spectrum Absorbs Red Yellow and Green bands • Lustre: Vitreous Heating of Sapphire will burn out the silk within the stone and is standard practice. CUTTING This mineral cuts extremely well but polishes differently on different facets. Orange peel is a problem with sapphires and will require pre-polishing with 3000 Diamond grit. At times sapphires will suffer from planes of hardness where cutting one facet will be extremely fast and yet another will take forever to cut. Pleochroism is mostly strong and should be orientated to give the best colour (strongest). Use a fast speed only for cutting (approximate 1000 to 1500rpm). Polishing can prove a problem with some facets due to orange peel so it is best to use 50,000 Diamond grit on a Tin/ Lead Lap that is medium to dry. Use Olive Oil as the base lubricant and spread over the lap. Wipe over the lap with a tissue and then dab polish powder around the lap and spread with a finger. Should this combination prove to ineffec- tive try adding a small amount of vinegar on the lap. Use a slow to medium speed for polishing (100 to 500rpm) The gem has an unusual high lustre and therefore can be cut as a mixed oval but is best suited to standard type bril- liant cuts. Cutting as a rectangle cut does improve the colour but can do the gem an injustice because off its Pleoch- roism. Crown Angles Pavilion Angles Main: 38° Main: 42° Girdle: 43° Girdle: 43 or 44° select your poison Star: 23° BIG TREV October 2009 Issue How Safe are Your Work Practices? 3 Pictured left, Happenings from new club around the Club member intricacies of basic silver- smithing. Lovely to see most of our wanderers return to the club. Last Wednesday was like a family reunion, with everyone Thanks to Bill’s there, everyone talking at once and much catching up efforts in apply- done. ing for commu- nity grants, the The club has the camera that goes with the new micro- club now has a scope and plans are underway to revamp the small kit to assist microscope room so that photos can be sent to the members with computer for editing and printing with the new printer. As the identifica- soon as this is all complete, challenge yourself to learn tion of gem the ins and outs of this setup. Computers with their stones. The capabilities are definitely here to stay and they extend our instruments in knowledge by a massive extent.