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Natural Science Forum / Earth Science / Mineralogy / December 2004Q: Left-handed quartz
Does anybody have or know of a source of natural (e.g., lascas Grade 1) or synthetic (z-plate, no seed in the active volume) extremely perfect and flawless left-handed quartz? We need a minimum of four 1-inch cubes (or equivalent volume in a larger stone) of absolutely flawless optically left-handed quartz [crystallographic space group P3(1)21] for a physics experiment. http://www.mazepath.com/uncleal/qz.pdf All commercial cultured quartz production is optically right-handed [space group P3(2)21]. Left-handed quartz is custom grown for optical components. Our quartz grower exploded his autoclave, putting us four months off schedule. We do not know of any other. -->Brazil (optical) and Dauphine (electrical) twinning are absolutely unacceptable. Does anybody have or know of a source of natural (e.g., lascas Grade 1) or synthetic (z-plate, no seed in the active volume) left-handed quartz that meets our extreme needs? Thank you! Post here or to the e-mail address in the pdf above. Just for fun... The procedure for orienting and determining handedness is described quite nicely in "Procedures in Experimental Physics" by John Strong, et. al., 1938 (reprint 1986). <http://www.amazon.com/exec/obidos/tg/detail/-/0137235771/104-5595925-8279142?v=glance> Also, Henry E. Paul from "Book Three of 'Amateur Telescope Making'" (1953 edition by Scientific American) on "Building a Birefringent Polarizing Monochromator for Solar Prominences." Starting on page 376 it describes acquiring, testing (and building the test equipment), properly aligning, and polishing optical quartz. Finally, optical handedness is defined in the opposite direction to geometric handedness. That is why optically left-handed quartz is geomtrically righthanded, space group P3(2)21. The sense of helicity is in fact identical in both cases. We specifically need untwinned single crystal optically left-handed space group P3(1)21 quartz.  SignatureUncle Al > Does anybody have or know of a source of natural (e.g., lascas Grade > 1) or synthetic (z-plate, no seed in the active volume) extremely > perfect and flawless left-handed quartz? Snip for brevity. The distribution of L/R quartz in nature is about 50-50. Bulk quartz crystals for oscillators were sorted using a polariscope, which revealed the handedness, and any twinning present. Best bet in absense of synthetic crystals is to obtain a batch of natural optical quartz and sort for left-handed crystals that are untwinned. Older lab procedure books give a good explanation of the process. Henry Barwood > > Does anybody have or know of a source of natural (e.g., lascas Grade > > 1) or synthetic (z-plate, no seed in the active volume) extremely [quoted text clipped - 8 lines] > and sort for left-handed crystals that are untwinned. Older lab > procedure books give a good explanation of the process. Upon further research, natural quartz is unsuited to the task. We need a hydrothermal grower of optically left-handed quartz, space group P3(1)21. Does anybody know of such? All commercial cultured quartz for electronics is optically right-handed, space group P3(2)21. (Optical and geometric helicity are defined in opposite directions. The sense of helicity is in fact consistent.) The procedure for orienting and determining handedness is described quite nicely in Procedures in Experimental Physics by John Strong, et. al., 1938 (reprint 1986). http://www.amazon.com/exec/obidos/tg/detail/-/0137235771/104-5595925-8279142?v=glance Also, Henry E. Paul from "Book Three of 'Amateur Telescope Making'" (1953 edition by Scientific American) on "Building a Birefringent Polarizing Monochromator for Solar Prominences." Starting on page 376 it describes acquiring, testing (and building the test equipment), properly aligning, and polishing optical quartz. The bad news is: H.R. Gault, "The frequency of twin types in quartz crystals." American Minerologist 34 142-162 (1949) Clifford Frondel, "Characters of quartz fibers," American Minerologist 63 17-27 (1978) From Gault, TABLE 2. FREQUENCY OF TWIN LAWS IN QUARTZ CRYSTALS Locality Rnt Lnt Rd Ld Rb Lb Rdb Ldb Total Arkansas 12 12 99 87 12 8 30 35 295 % 4.1 4.1 33.6 29.5 4.1 2.7 10.2 11.9 Pennsylvania 4 3 16 12 0 0 159 153 347 % 1.1 0.8 4.6 3.4 0 0 45.8 44.1 Tintic, Utah 69 65 16 15 3 0 0 0 168 % 41.1 38.8 9.5 8.9 1.8 0 0 0 Herkimer, NY 14 13 1 2 3 2 3 6 44 % 31.8 29.5 2.3 4.5 6.8 4.5 6.8 13.6 Maryland 9 12 7 10 0 0 0 0 38 % 23.7 31.6 18.4 26.3 0 0 0 0 Alaska 0 0 30 40 0 0 21 20 111 % 0 0 27 36.1 0 0 18.8 18 *R=right; L=left; nt=no twinning; d=Dauphiné; b=Brazil; db=Dauphiné-Brazil. Dauphine twin with c the twin axis Total right-handed or right-handed dominant 518 or 51.6% Total left-handed or left-handed dominant 485 or 48.4% Grow it or nothing. It would take as long and cost as much to collect enough candidate rock crystal and analyze it, with no guarantees. Natural - humbug! SignatureUncle Al http://www.mazepath.com/uncleal/ (Toxic URL! Unsafe for children and most mammals) http://www.mazepath.com/uncleal/qz.pdf Uncle Al <UncleAl0@hate.spam.net> wrote in message Snip > The bad news is: > > H.R. Gault, "The frequency of twin types in quartz crystals." > American Minerologist 34 142-162 (1949) > From Gault, > [quoted text clipped - 21 lines] > enough candidate rock crystal and analyze it, with no guarantees. > Natural - humbug! Despite the results listed above, the frequency of usable optical quartz in natural crystals is fairly high. Gault was listing any twinning, etc. because for oscillators, a crystal with, say, 10% twinned material would be rejected. Now that piece might be 20 x 20 cm in size and contain a large untwinned area, but would still be rejected. You used to be able to buy such rejects from government stockpiles in 220 pound lots for a very low price and sort out some magnificent optical material. In any event, good luck in your search. HB > Uncle Al <UncleAl0@hate.spam.net> wrote in message > [quoted text clipped - 41 lines] > > In any event, good luck in your search. "8^>) The cost of labor for qualifying raw material starts looking like the cost of growing it. I've got inquires into Zeiss and others about optically left-handed quartz in stock. I'm talking with a major German lascas supplier who culls for Grade 1 for crystal balls. I've tried to contact the national strategic stockpile. That is like shouting into a manure pit. We can do all sorts of scientific clever, but given sudden broad knoweldge of the situation I'm going to recommend the engineering approach - do it right, don't do it over. We chose quartz because of its excellent calculated numbers and inexpensive availablity. The first out of three will suffice. Everything else is worse. SignatureUncle Al http://www.mazepath.com/uncleal/ (Toxic URL! Unsafe for children and most mammals) http://www.mazepath.com/uncleal/qz.pdf Don't know if can find the 'handedness' of the boules he has on hand, or perhaps put you in contact with the factory - but Grady Harris is a great guy and he will help if he can. (I and many I know purchase faceting materials from him). Don't expect eh catalog to be current nor should you expect great email responsiveness. I'd suggest calling him. http://www.creativegems.com/ Carl 1 Lucky Texan >>Uncle Al <UncleAl0@hate.spam.net> wrote in message >> [quoted text clipped - 56 lines] > inexpensive availablity. The first out of three will suffice. > Everything else is worse. Signatureto reply, change ( .not) to ( .net) > Don't know if can find the 'handedness' of the boules he has on hand, or > perhaps put you in contact with the factory - but Grady Harris is a [quoted text clipped - 3 lines] > > http://www.creativegems.com/ [snip] No e-mail! I'll try harder. They do list clear quartz in their catalog. Thank you. SignatureUncle Al http://www.mazepath.com/uncleal/ (Toxic URL! Unsafe for children and most mammals) http://www.mazepath.com/uncleal/qz.pdf > > Don't know if can find the 'handedness' of the boules he has on hand, or > > perhaps put you in contact with the factory - but Grady Harris is a [quoted text clipped - 7 lines] > No e-mail! I'll try harder. They do list clear quartz in their > catalog. Thank you. According the following link; http://www.tedlind.net/Properties.htm There may be an English company manufacturing left-handed quartz. Also, if I understand it, any quartz first heated to 573*C and subsequently cooled will have a 50% chance of becoming left handed! If true, you may be able to create your own material! Carl 1 Lucky Texan > > > Don't know if can find the 'handedness' of the boules he has on hand, or > > > perhaps put you in contact with the factory - but Grady Harris is a [quoted text clipped - 15 lines] > subsequently cooled will have a 50% chance of becoming left handed! If > true, you may be able to create your own material! The beta-transition at 573 C leads to uncontrolled twinning on cooling. Morion sold its last left-quartz to Livermore two years ago. Onto tedlind! We've done some calculations with for benzil. Quartz is still a strong second. Berlinite, AlPO4, is slightly better than quartz and not grown at all to large size. It also has inverse solubilty vs. temp. SignatureUncle Al http://www.mazepath.com/uncleal/ (Toxic URL! Unsafe for children and most mammals) http://www.mazepath.com/uncleal/qz.pdf |
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