Evening Star Newspaper, March 24, 1935, Page 53

THE SUNDAY STAR, WASHINGTON, D. C., MARCH 24, 1935—PART FOUR. F—=3 WASHINGTON’S SINGLE GEM CUTTER AND HIS WORK <« By Gene Harry Day. | CAN both the classified sections of the city directory and tele- phone book until your eyes are red and bleary, yet you will | discover ’nary a professional lapidary or lapidist listed as resident and active in business in the Dis- triet or nearby Maryland and Virginia. Not a single gem-cutter in Washing- ton with her half-million population and the richest holdings of privately- owned diamonds, rubies, sapphires and emeralds of any municipality of com- parable size in the world. A lapidary is a gem-cutter who by the skill of his trade—it has been a secret art handed down like a valuable legacy from father to son—transforms crude and sometimes ugly stones into scintilating, irridiscent sources of ap- parently radiant brilliancy of such beauty that it beggars both pen and typewriting vocabularies to even at- tempt to describe them. Washing- tonians’ precious gems, when and if they need recutting, are sent either to Philadelphia or New York City, where expert lapidists re-angle their facets and polish them to new and perhaps different zeniths of brilliancy. ‘True to tell, there is no professional lapidist in the District, but there is at least one man who is capacitated to facei and polish precious stones, al- though his experience to date has been confined to the cabochon and facet cutting of semi-precious stones. ‘This man is practically self-trained in his intriguing hobby, yet curious to ‘ell, he has perfected and applied tech- nical inventions to the fascinating art which merit reproduction and util- jzation in the workshops of the pro- fessional lapidists. The Washingtonian who has dabbled successfully in that long secret wonderwork of cutting dia- monds and other gems is Albert H. Bumstead, chief cartographer, or map- maker of the National Geographic Society. He is a master at finding new technical riddles to solve—and then solving the selfsame to the queen's taste. His particular delight, in fact. consists in developing new methods as well as technical “shortcuts” for the accomplishment of precise, mechanical | work which involves seasoned skill | and particular patience. | | UST for the sake of variation, let's . scramble and customary formula | for the once and pause to discuss the | diamongds, or finished products before we describe in detail how Mr. Bum- | stead prepares his semi-precious stones for exhibition. even as diagnonds are | prepared for commercialization. ‘Thoughts of diamonds have streamed | through people’s minds since those gems were first made available for | ownership and display. Diamonds | from then until now have been peren- | nial puzzles—real riddles of creation A philosopher named Steffans once said: “Diamond is quartz which has arrived at self-consciousness.” Subse- quently, an internationally known geologist parodied Steffan’s statement | by remarking that “Quartz is diamond | which has become insane.” | Albeit, the exact formation of the diamond even today is an unsolved problem, despite that science is now able to manufacture synthetic dia- monds in extremely minute quantities. ‘The diamond is the hardest known | substance in nature. Its reflecting | power and refractive energy exceed | those of all other colorless bodies, | while in the perfection of its pellu- cidity, the diamond is without rival. Strange to say, some diamonds are 50 hard that it is impossible to cut and polish them into able gems. But those harder-than-hard dia- monds notwithstanding, are ulti- mately harnessed for utilitarian serv- ice, being used for rock-boring pur- poses. Here actually is news for the record book. Diamonds which are stolen and their whereabouts practically known to the police are termed “hot” gems in the vernacular of the under- world. They are usually so “hot” that fences and traders who handle stolen goods are afraid to offer them for sale. They may be “hot” but their temperatures never attain points where the gems explode with a big bang and destructive blow-up as do other gems of that family, tribe, spe- cies or whatever you want to call the organization to which the precious stones belong. Experts tell me that it is not uncommon for a diamond to explode soon after it reaches the surface. Certain gems have even burst in the pockets of miners, or have disintegrated when held in the warm hand. The large crystals are ! more liable to burst than the smaller Ppieces. Incredibly valuable gems | have been destroyed in this manner. | Time was, so the story goes, when cunning dealers were not averse to , permitting responsible clients to handle or carry in their warm pockets large crystals of diamonds in the rough which had been freshly mined. If the diamonds blew up and were @ Capital Owns Many Diamonds and Other Precious Stones, But There Is Only One Lapidary and He Grinds and Polishes Stones for the Fun of It— Mystery Connected With the Craft amount of pure iron, free from sul- | phur, silicon, phosphorus and the like, | in a carbon crucible with pure char- coal from sugar. Subsequently, put | one-half a pound of this iron in the | body of an electric furnace with a powerful arc just above it betweeni' carbon poles, utilizing & current of 800 | amperes at 40 volts pressure. The | iron melts rapidly and saturates self with carbon. After a few mi utes of heating at a temperature of 4,000 degrees Centigrade, the current should be cut off and the dazzling, fiery crucible plunged beneath the sur- face of cold water where it should be held until it sinks ®elow a red heat. Iron increases in volume just as it passes from the liquid to the solid state. The sudden cooling solidifies the outer layer of iron and holds the molten mass inside of this exterior coating. The expansion of the inner liquid on solidifying produces a stu- pendous pressure which causes the dis- solved carbon to separate out into a transparent, dense, crystal as a dia- mond.” | All indications point to the fact that the diamond genesis occurred in' nature at great depths under enor-. mous pressure. The explosion of large | diamonds on being brought to the| surface shows extreme tension. More | diamonds are found in fragments and | splinters than in perfect crystals and in no case have the pieces been dis- | covered which coud be fitted together satisfactorily. Some diamonds when examined scientifically show cavities which contain gas imprisoned at con- | siderable pressure, which probably | causes them to explode under exactly the right conditions. The most com- monly accepted theory of the origin of diamonds is that they were pro- duced from masses of molten iron| once held in the earth at extreme depths, under great pressure and nti high temperature with supplementary | carbon which was ready to crystallize | out on cooling. The many molten | masses of iron with variable contents of carbon, different kinds of coloring | matter, solidifying at different degress of rapidity came in contact with water which eroded through the rock at in- tervals throughout long periods of geo- logical time. Terrestrial outburts and | upheavals resulted which undoubtedly produced the volcanic pipes, scattered | chiefly throughout the Kimberly fields of South Africa that contain the world’s supplies of diamonds. covered Many Importanit Facts. HE mysterious art of gem-cutting which was born some 60 centuries ago, has existed for generations with- out reference books or bibliography. An art which is parent’of one of the world'’s wealthiest trades is prac- tically unknown in scientific litera- ture. Not a single book about it has ever been printed on an American press. Creation’s record collection of books at the Congressional Library contains neither tome, text book or treatise concerning the fascinating activities of both ancient and modern lapidists. Veiled in secrecy from its inception, this manipulative mastery of both gems and beautiful stones has husbanded its mysteries to the point where they are almost inviolate. Of all the unknown arts, it has rated as the most occult. Rival lapidaries have lived and died without revealing any of their secrets. Crimes were committed, blood was shed, but not even the wrath of royalty nor the machinations of the underworld were adequate to loose anything more than fragmentary facts about cabochon cutting and the facetting of precious and semi-precious stones. When Albert Bumstead responded Top, at left: These internal grinders are made of either poplar or maple, the abrasive paste being restrained in the cut-out portion by centrifugal force. Used in cabochon cutting. | products of the amateur lapidary’s stone by a process invented by Mr. Bumstead. Center, top: Beautitul art. Top, right: Squaring the gem Lower left: Checking the angular position of stone before cutting a new facet. Lower right: Polishing the gem on a hard felt wheel, with tin oxide as an abrasive. A final step in cabochon cutting. stone cutting he enlisted in a hobby whosiperplexlv,ies are almost as baf- fling s the mathematics of a fourth dimension. Always an admirer of precious stones and precise, m¢- chanical work, he now dedicates his idle hours in his basement workshop to the solution of the “doubts” which develop from the lack of published lapidary lore. When the writer dropped In to visit Washington’s only gem-cutter recently he told more than a little about the origin of the two types of gem-cutting and how they | transform raw material into superbly attractive stones. | ""For your information, it is interest- {ing to note that the engraved seals | of Babylon and the scarabs of Egypt were the ancient progenitors of mod- gem-cutting attained its greatest artistry, during the days when sapphire points and bow drills were used. Altogether, there are now 125 gem stones, including both precious and semi-precious varieties which are handled regularly in the workshops of professional and amateur lapi- daries. Approximately one-half of | these are suitable for cabochon cut- ting, but the finer and more costly ones yield their maximum trove of beauty only when cut facet. Cabochon cutting or flat work involves the use of the mud saw for splitting, slitting | and slicing the stone, carborundum | grinding wheels for roughing and | shaping the specimen, internal grind- ers of poplar or maple for polishing |away any surface scratches and to the blandishments of semi-precious ' ern gem-carving. About 500 B. C. wheels of felt for buffing purposes. Cabochon cutting is relatively sim- ' ple. according to Mr. Bumstead., who by its application has made beautiful cuttings of smoky quartz from New ; jasper | from Maine, Amazon stone from Vir- | Hampshire, lapidolite and ginia, moss agate.from Montana, as | well as petrified wood, amethyst, sun- stones and many others. The other necessary equipment includes a small motor and a line shaft with a tapered screw chuck attached to both ends. The vertical mud wheel is a disk of sheet iron, bronze, copper aluminum about 12 inches in diame- ter, with a tin shield above the wheel to prevens splashing and with a metal container for the water and abrasive so placed that from 1 to 2 inches of the wheel's periphery dips into the solution at the lowest arc of its revo- lution. The stone to be cut is either held by hand, in a sliding carriage or by an overhead swinging arm. Although diamond saws are available for slicing, most amateurs eschew their use because of the added cost. "AP’I‘ER the stone is sliced out it is roughed into shape on the car- borundum wheels, these grinders be- ing kept wet with a moist sponge dur- or | Induces Albert H. Bumstead to Find Out Just What It Is All About and He Has Dis- | ing that process,” Mr. Bumstead told | me. “Strong hands come in handy,’ | he continued, “where the specimen | is held in the fingers. Its position is changed frequently to effectualize efficient shaping. Opaque stones such as the innumerable varieties of quartz | and colorless agates are customarily { cut cabochon to best show up their colors. curves in the rounded upper surface of the stone as accurately as possible and to continue the grinding until all defects in curvature are elimi- nated. “Even after the carborundum grind- . ing has been completed, there are | { still diminutive, flat surfaces and | angles in the stone surface which | must be removed. In order to elimi- nate such and perfect the specimen, it is mounted with sealing wax on the | end of a stick with the flat face of the stone seated against the stick end. After the wax hardens the specimen stone is smoothed out and produces a very fine-grained surface | by polishing it on one of the internal grinders. The stick facilitates this process as it enables the artisan to hold the stone in the internal grinder under considerable pressure. This grinding continues until all the scratches left by the carborundum wheel are eliminated. Every once in 50 often, the stone has to be removed it under the microscope. Magnifica- tion aids in revealing the tiny surface blemishes which otherwise would escape attention, but which must be removed. The stone is then finished on the two internal grinders, one coarse and the other fine.” In preparing the specimen for final polishing, the stone, stick and hands of the artisan must be rinsed carefully in water to remove all traces of car- borundum grit. Then the stone is polished on a hard felt polishing | wheel, tin oxide in water being used as the abrasive. the finish polish depends upon the faithfulness with which all the pre- vious operations have been performed. The final buffing is 1n no sense a cor- rective measure which will compen- | sate for previous slack or slighted ‘workmanship. | ~ By use of the axle and one wheel of a discarded model T flivver, Mr. Bumstead has devised a special hori- | zontal wheel, or lap, for polishing | large flat surfaces. This equipment is | linked to the line shaft by means of THO damaged irreparably, the dealers held || those persons in whose possession the diamonds then were responisble for such losses. British, German and French diamond traders, who for- merly traveled once, twice or thrice annually to South Africa after dia- monds, commonly carried raw pota- toes in which they embedded the fresh diamonds that they bought from miners and natives in order to insure safe transit to Europe for the costly but “raw” gems. You can pretty well appreciate that the best steel is relatively soft when measured by the average hardness of diamonds when you familiarize your- self withrthe following test. Experi- mentors, time and again, have placed diamonds on the flattened apexs of conical blocks of steel. When hy- draulic pressure is applied in effort | g& to crush the gems against the steel | surface, something entirely different | B from what you might expect occurs. If the diamonds are flawless, they actually are squeezed and pressed by ‘ the hydraulic force right into the | : blocks of steel without injuring the gems a single iota. B | 'AN you imagine any experience more rare and epochal than to ! be able to read by the light of a dia- | mond which you might own, if you | were wealthy? That phenomenon has | really happened. green diamonds can be made to phos- | phoresce in a good vacuum to the | Certain beautiful | & | AiE ) V \TSOUNOED LIKE 5 SOME BODY SAID, THIS (S NA,YO / CHI SOMEBOOY SAVD SOM~ extent that they will give off as much light as an ordinary candle. This light, however, is always pale green, tending toward white. After exposure for some time to sunlight, many diamonds will glow | & when placed in a dark room and seem | suddenly endowed with strange lum- fnous qualifications. Some diamonds are fluorescent, appearing milky in sunlight. In a vacuum exposed to a high tension current of electricity, diamonds phosphoresce in different colors, most South African diamonds shining with a bluish light. Diamonds | from other localities emit bright blue | apricot, pale blue, red, yellowish, green, | orange and pale green light. Sclence reports that invariably those diamonds | B which are fluorescent in the sun are | the most phosphorescent gems. If you are chemically minded and wish to make your own diamonds— synthetic gems are now possible but can be made in only minutely micro- scopic amounts—here, in brief, is the ‘mflmlon to follow: “Pack a small . " ~\al W / 2! MA,///{ ; 0 Nlhof3 s e a g’ ¥ e~ P s == ) ) SE WERE THE HAPPY DAYS— “Phone Memories” A ASONOF AGUN \E YOU CANY, HEAR OVERE e LR EMEMBERS WHEN A TELE F PHONE OPERATO HAD TIME TO SAY SOME THING ELSE ___J BESIDES,/NUMBER! PLEASEN AN | —HRILL YoL OSED TO GETWHEN:- HEARING THE HOM “THROOGH “THE TELEGQRAPH COLES D s —" THANK' yw% G THTIMES, MEMBER. "r/-uz ONE 2 THEYEARS SONG HiT; a_ IEC HE cop —By Dick Mansfiel(‘i‘ courPLE OF YERST CowNER BOXES WITH A ROSINED STRING GAVE US — T OOR FiRST REAL TELEPHONE THRILL, _ L . REMEMBERI\’LL Bs SAY YOO NO. . N5C ATOR AT (At ¥V \evoey Te=s= o] WHAT DO yoU REMEMBER T ANSWER O LAST WEEKS (ALOVESTION, HAT DARING FEAT Took PLACE A SMOKE STACK & CA.AVE. N-\W. o7 \899 ? TOP OF “THE OLN CAP- oL “TRACTION SMOKES TACK. | muswufi'é?w. It is essential to cut the| from the grinder in order to examine | The excellence of | a special pulley for operating the | wooden lap whose upper face, covered | with a taut plece of canvas, is slightly | convex. This canvas holds the abra- sive on the rapidly rotating surface. ‘This buffer is particularly adapted for ‘pommng large surfaces of petrified | wood, smoky quartz and similar speci- | mens. In facet-cutting (diamonds are cut in this manner) such semi-precious stones as rock crystal, smoky quartz, citrine and amethyst are first roughed to the approximate size desired on the coarse carborundum wheel. Then the table, or top face of the stone, is ground flat and smooth previous to mounting it with sealing wax or chaser’s cement on the end and exactly at right angles to the length of a rounded stick. The specimen is mounted with its table flat against the squared end of the stick. An ingenious device used by Mr. Bumstead facili- tates this squaring procedure. The arrangement is such that while the sealing wax is still hot, the stick is .| placed in the grooved channel of this appliance and pressure is applied: the stone is seated with the table truly squared with the axis of the stick. | Mr. Bumstead next clamps the stick to another apparatus which he has contrived, which governs the position of the stone during the grinding on the horizontal wheels, or laps. The | device is made from the graduated | base of one of the sun compasses | which Mr. Bumstead originated, the set-up being such that the stick can be turned through different angles in | order to grind and polish successive | facets. The stone is now in position | to grind its base, or pavilion faces, which give maximum brilliancy when | cut at an angle of approximately 43 degrees from the plane of the girdle, the girdle being the largest circumfer- ence of the stone. The above dimen- sion holds true only if the gem fs beins | cut from some variety of quartz. R. BUMSTEAD uses an instrument | called a clinemometer in adjust- ing the slope of the stick. On the | graduated circle of this device on the | end of the stick holding the stone, the | angles are measured for turning from one facet to the next. This crafts- man’s work bench is equipped with a leveling device for making the grinder truly horizontal. These detailed opera- tions are fundamental in facetting and typifying the extreme precision and accuracy essential for satisfactory results. In facet polishing. the lapidist has to exercise extreme care not to scratch the faces of the stone. Polishing is performed on a disk wheel or lap of tin with tin oxide and water used as the polishing agent. The facets are polished in exactly the same order that they were cut. The adjustments of the holding device are made very accurately during the polishing and the stone is inspected frequently under a magnifying lens to assure that the polishing is carried far enough to re- move all of the marks of grinding and yet not so far as to injure the shape of the adjoining faces. This finishes the cutting and polishing of the pa- vilion facets. A smooth, solid tin wheel will scratch the stone. To prevent such a catastrophe, the wheel is scored with long radial lines about one- quarter inch apart cut with a pocket- knife or razor blade. The wheel is then run fairly fast and its surface is smoothed slightly by using it to polish agates with tin oxide and water. That treatment gets the tin lap in desirable condition, so that it will polish the facets without scratch- ing or otherwise damaging them. One other precaution is to use a very thin mixture of the tin oxide and water for all facet polishing after the wheel has been etched or scored with steel and smoothed with agate. Clear quartz, smoky quartz and ame- thyst can 2ll be made to bloom in the pristine glory of brilliant colors. Topaz is one stone which cannot be polished in this manner, as it per- sists in getting scratched. It can. however, be polished satisfactorily if ruby powder is used instead of tin oxide There is only one way of producing diamonds of greater brilliancys than those resulting from the facet system of cutting. That consists in making synthetic diamonds. Certain colors are produced in the synthetic dia- monds, which are more beautiful than any ever seen in the natural stones. However, there is a distinct limit to synthetic diamond produc- | tion, as such simulations can now | be produced only in microscopic sizes. Science gives little hope that syn- thetic diamonds will be produced potentially in such size and on such scale as to compete with the true | diamonds—valuable gems imported chiefly from South Africa. Most gem- cutting by professional lapidaries is done abroad, as the foreign specialists | work . so cheaply that American | lapidists are unable to compete with them. — Controlling Crab Grass. These early Spring days are not | too late for development of good lawns | and the battle against crab grass can | well be started at this time, according to J. T. Mulford of the Department | of Agriculture. Crab grass being an annual has no footing in the lawns at this time, and, if the regular lawn grasses are prop- | erly fed now, when crab grass time | arrives the present grass will be suffi- ciently vigorous to discourage growth of the crab grass. Watering during June and the Summer months en- | courages crab grass and should not | occur if the other grass is well es- | tablished. | A feeding schedule in which a pound of cottonseed meal or similar fertilizer is used per 20 square feet at this time, to be followed in June and | each month thereafter by 1 pound of | ammonium sulphate per 800 square feet, is considered most likely to pro- duce good grass. For second-year feeding, bone meal is substituted for the cotton seed meal and that alter- nation is maintained - Mr. Mulford also advises leaving the grass clippings on the lawn, as the effect is to produce a mulch which not only conserves the moisture in the soil but at the same time provides a source of organic matter which the soil re- quires. When top soil is added to a lawn to improve the ground, not more than one-eighth of an inch should be added in any one year. Vo Rose Problem Solved. Rose growers in this locality who are bothered by the rotting of buds at the base before they open can overcome this difficulty in part by spraying every 10 days with Bordeaux mixture. The trouble usually is due to stem canker or black spot, both of which can be controlled by the spray. Certain types of roses do not thrive in this climate and these should be replaced by those which do well here | in open ground. Generally speaking the lighter cole |ored types are less likely to thrive i than those of d?fl‘ hue,