Meeting # 1598

4:00 P.M.

February 19, 1998

The Making of a Lapidary

by

George William Smart, CSM

Certified Supreme Master Facetor,

American Society of Gemcutters

Assembly Room, A. K. Smiley Public Library

SUMMARY

This paper describes that a Lapidary is both a person and an art whose interest in gemstones includes collecting, displaying, cutting, selling, mounting, and otherwise showing an interest in beautiful cut and polished gems. The emphasis in on faceting, that is, cutting certain faces on a transparent stone so that it will reflect or disperse light in a way that is pleasing to the eye.

We trace the interest of one person from complete ignorance of the process, to a limited understanding of how a gemstone is transformed from a ragged crystal into a sparkling beauty that finds its place on a lady's finger.

Reference is made to gems and minerals in the Bible, and ancient use of stones to decorate and enhance various objects. A brief description of precious gems refers to diamonds, emeralds, sapphires and rubies. Synthetic gems are described.

Keywords: Gemstones, lapidary, faceting, cutting-evaluation, precious stones, synthetic stones, Bible stones, Quartzsite, diamond, ruby, emerald, sapphire.

BIOGRAPHY

George William Smart was born and raised in Glendale, California. He graduated from Gordon College In Boston, Mass. in 1936, and took graduate seminary degrees at Gordon Divinity School, Berkeley Baptist Divinity School and Central Baptist Theological Seminary. Additional studies took him to the University of Nevada, and the University of California at Berkeley. He is married and has two children.

He was ordained to the Christian Ministry by the First Baptist Church of Georgetown, Mass. which he pastored until 1939 when he was appointed by the American Baptist denomination to the Tahoe Indian Parish in Nevada. After 14 years in Nevada, he became Chaplain of the federal government's Haskell Indian Institute in Lawrence, Kansas. Ten years Bier as President of the Cook Indian Theological Seminary in Phoenix, he directed the building of a new campus in Tempe. Two 'pale-face' pastorates followed in California¾ the First Baptist Church of Calimesa and Grandview Baptist in Grand Terrace.

His published History of Nevada Indian Missions was part of his Doctorate of Theology studies at Central Baptist Seminary in Kansas City, KS. He was president of the National [Fellowship of Indian Workers, and of Ministerial Associations in Lawrence, Kansas and Carson City, Nevada. this Nevada friends of the Washo Tribe named him Honorary Chief Wa-Pai-Shone, for his service to the three major tribes in Nevada¾ Washo, Paiute, Shoshone.

He is a member of the First Baptist Church in Redlands, maintains a General Class Ham Operators license, is a Certified Supreme Master facetor of the American Society of Gemcutters. Other hobbies include bonsai, orchids, and dabbling with woodworking. He has enjoyed the humane and ethereal atmosphere of Fortnightly Club since 1989.

INTRODUCTORY

Before I retired frown day to day activity in the practice of Ministry, I had often wondered if I would become, when I did retire, an obstacle in the daily life of my wife. How could I avoid being under foot?

Actually I had hoped that the bag of hobbies I had been neglecting, filled with activities crying for attention, would be opened so that some of them might find expression. During my working career I seldom had enough time to indulge myself in such 'trivia'. But the Lord was good in allowing some leisure after my first retirement, and I indulged myself in a long-forgotten enterprise. I have entitled this paper "The Making of a Lapidary".

What is a lapidary? A dictionary describes LAPIDARY as both an activity, and a person. It is derived from a Latin word meaning stone. Is it a display of stones like those of Stanley K=fmacher sometime at our local museum? Is it a company like Covington Engineering and Lapidary at the corner of Texas and Colton avenues? Is it a gem dealer in the Malt or one who cuts' polishes, or engraves a stage? or maybe the word refers to the an itself? When I was first called a lapidary, I didn't know whether to accept or deny the appellation.. Actually a lapidary is all of He above!

The veteran lapidary, gemologist, and diamond cutter, Gerald Wykoff, writes, "Lapidary--especially the faceting disciple--commands a full appreciation as a skill of the highest and most interesting order.

"Most people react in simply frank amazement to the apparent ditty that must be involved In creating such incredible demonstrations of rigidly sequenced beauty. Yet the faceter will readily admit that faceting is a relatively simple procedure, easily taught and easily learned. However, it involves a whole series of collateral and diagnostic Kilts that influence the outcome. The faceter’s skill and decision-making are devoted to releasing the physical chemical, and optical personality of a gem material. A properly faceted aquamarine is a majestic sight, but no additional beauty can be achieved in this species of beryl than will be allowed by its gemological limits."

THE MAKING OF A LAPIDARY

My special interest in Lapidary was to facet gems. How did I become a Lapidary, and why? If you will bear with me, and allow me to recount some personal data, I will try to get on with it, and eventually get to some hard facts about stones!

As a child my only contact with minerals and crystallography was limited to viewing a quartz crystal in a display case at the home of a cousin on a deny ranch in Covina, CA.

In a college dormitory in Boston, Mass. I moved into a room with a supposedly empty closet. I found, however, a rock filled with amethyst crystals. It seemed to me to be a treasure.

For two summers I was employed as a door-to-door salesman in the state of Maine, selling Bibles. That was a tough job, for I was not born to be a salesman, nor did I care very much whether I learned. But tramping through rural roads of Maine, this Californian leaned to lice the Maine woods, and especially the wild strawberries and blueberries that grew In abundance.

More importantly, there were many stone quarries in Maine. This salesman discovered it was a rewarding and a unique experience to stop and explore a quarry, pouring through the detritus looking for crystals of various minerals, such as quartz, mica, hornblende, occasional garnets. He often sent some specimens home to the parents in California.

After beginning to write this paper, I discovered a long forgotten letter I had written to my father over 60 years earlier, ---in 1934 --- from the town of Rumford, Maine, where I was exploring quarries. The letter described a visit with a young geologist who took me out to see a tourmaline mine. He also gave me some samples of rough gem material, including Maine Tourmaline. Much to my surprise that letter included detailed drawings of his home-made faceting machine. My purpose in the letter was to suggest that my father build such a machine at home in California. Directions were included for using the machine to facet gemstones.

This interest in faceting in 1934 had completely left my mind, for I was under the impression that my concern for this hobby began only after my retirement in 1975 in Yucaipa The stored unconscious fascination became a lively conscious activity.

Back to New England. Stones that exhibited a crystalline shape fascinated me for I knew nothing about such phenomena. Nor did I know the names of more than two or three minerals. It so happened at the end of my senior year that I was chosen to be one of the college graduation speakers. Since I was majoring in religion I chose a gemstone theme, "Treasures of Darkness", using a biblical text which referred to the formation of crystals deep in the crust of the earth, treasures from the Creator. The prophet Isaiah gave this a religious application, whereby those in the darkness of sin might become beautiful jewels (i.e., persons) before the Creator. Upon later reflection, the speech unwittingly revealed to me that my love for these strikingly beautiful nature gems formed by the hand of the Creator was to become an enduring facet of my life.

Yews passed Eventually I became a missionary, serving among the Indians of western Nevada. Early on I was involved in erecting a stone church adjacent to the campus of the Stewart Indian school at Carson City, matching the brightly colored stone offices and dormitories of this government boarding school. For our Chapel we scoured the countryside, the mines, the hot springs, the stone outcroppings for building materials. Green, yellow, pink, slate, black, red rocks were hauled¾ load after load of dump trucks filled our building site. What a lesson in stone! But we found no crystals¾ until we started building¾ then various students brought from their home reservations, crystals of all sorts to be placed in our mission fireplace.

More years passed. No opportunity to pursue my interest. Eventually I found myself in Arizona, hiking down a trail into Canyon de Chelly. A guide called attention to some ants beside the trail. They were bringing up from their hole small round red grains of sand. But not by sand. They were tiny bright red, transparent garnets. Help yourself he said. What a surfing treasure, I thought, as I folded them into paper in my pocket.

Many more years passed. Finally Retirement. Living In California. During a visit to San Clemente, a cousin from the same family that had previously displayed quartz crystals in Covina, introduced me to the art of not merely collecting stones, using them for gems. Cousin George showed me crystals like I had never seen before. He showed me cabachons (which I had never heard of). Cabachons are stones of various colors and minerals that have been shaped and polished to fit into rings and belt buckles and bola ties. Generally dome-shaped. Then he showed me crystallized minerals that were beautifully transparent. Some of these he had faceted into beautiful gems set in rings or pendants. It all seemed so new! I had totally forgotten my earlier brush with lapidary fifty years before!

QUARTZSITE

By this tune, I was all eyes and ears. And when he offered me the opportunity to travel with him to Quartzsite, Arizona to attend a small gem and mineral show, I grabbed at it like a monkey snatching a banana from his keeper. A social and kinship relationship blossomed between two cousins and their wives around a new and thrilling hobby. With our trailers, we traveled to the desert surrounding Quartzsite‚ AZ¾ a tiny town of a few hundred souls that over the years was going to explode in the month of February to at least a million people¾ snowbirds and the rest of us! Camping was free, but if you had to buy water, it would cost plenty for a gallon. We took our own water from Yucaipa!

Let me tell you about the phenomena of Quartzsite! The gem and mineral club in Quartzsite had begun a rock and mineral show with only a few exhibitors in a small building. Snowbirds who were also rockhounds heard about the free camping among Bureau of Land Management sagebrush The few RV rigs grew each year as word spread across the country that something exciting was happening in the western Arizona desert. Before long thousands of RVs were spread across the sagebrush for miles in every direction. Tailgaters with their own brands of merchandise joined the show.

New groups opened new venues. The sale and display of gems and minerals, while still the main event, attracted those who had antique items for sale¾ china, handwork, telephones, cloth goods, jewelry of all sorts, games, hats, canes, tools, appliances¾ and eventually expensive RVs were on sales display, with price tags of hundreds of thousands of dollars. After ten to twelve years of attendance this interested customer (that's me!) called it quits; it became too difficult to get around the hordes of people who flocked to the event.

BECOMING A LAPIDARY

During our travels there, with a few modest pieces of equipment, I began working with gems and my cousin took me under his wing. He had moved to Hemet. He invited me and my wife to spend a day in his mobile home. He sat me down at his Graves faceting machine. For four hours in the morning and four more hours in the afternoon, he taught me the art of faceting a gemstone. It was a pink synthetic sapphire, cut in brilliant round. Yes, I am wearing the sapphire today in a ring!

Eventually I found a faceting machine advertised in the Greet Sheet. It happened to be a duplicate of the one on which I cut my first stone. By this time I was thoroughly hooked on the great beauty that came from turning a crude rough crystal stone into faceted gem that reflected light and dispersed colors in all directions. What a thing of beauty!

We four cousins continued to trailer together to Arizona until one year my companion confided to me that this would be his last trip. He had cancer, not responding to treatment. By this time I had entered a few gem competitions and won a ribbon or two in second or third or last place. I had joined the American Society of Gemcutters, and began sending my gemstones for evaluation. I came to be rated a guildsman and a journeyman, hoped to become a certified master before my mentor in Hemet passed on to his heavenly reward. He departed this life before I could tell him that one of my stones had fortunately passed the scrutiny of a board of judges with a score of 99.9%, winning a Pinnacle Award. The society sent me notice that I had become certified as a Supreme Master of the lapidary craft.

FACETING A GEM

How is a gem faceted? A rough piece of aquamarine, for example, is placed on the end of a brass rod called a dop-stick held fast by a wad of softened wax. The rod is secured in the faceting-machine spindle. It is lowered on to a round flat diamond-charged lap, much like an old phonograph record, that turns at variable speeds. With water dripping from a tank to keep the process cool, the operator chooses an angle from the protractor. Since this gem is to be cut as a round brilliant, an index plate will turn the stone to the proper location as guided by the cutting instructions. Moving from a coarse grind to ever smaller, all facets on the underside are cut and polished. The bottom half of a gem is called the pavilion. The dopstick and stone are removed from the machine; the stone is reversed by transferring to another dopstick and reinserted in the machine. The upper half (called the crown) is now cut. The last facet to be completed is the flat top called the table. The round edge, called the girdle, is usually cut as part of the pavilion. 14,000 grit diamond powder on a tin/lead polishing lap will polish the aquamarine, and most every gem available.

What have I learned during the fifteen years I have pursued this lapidary hobby? I leaned a little bit about numerology. I learned a little bit about gemstones¾ precious, semi-precious, and plain beauties. I learned a little bit about crystallography, and the characteristics of different minerals. I learned a tiny bit about their molecular structure. I learned about the specific gravity of stones, their refractive index, their chemical composition. I learned individual stones had differed refraction and reflection, dispersion and fluorescence . I learned the difference between a marquis cut and a round brilliant, an emerald cut and an oval. I learned something of various grits to abrade a stone into shape, polishing it, using diamond charged laps, etc., etc.

If you will note the accompanying diagram, you will see the names of the various facets, the Girdle circles the stone and delineates the top and bottom. The upper half (actually upper third) is called the Crown, bottom is the Pavilion; the point at the bottom the Apex or Culet; the flat top is the Table. The Main facets in the Pavilion are at such an angle that they reflect light upward through the Table. Star facets surround the Table, and girdle facets are above and below the girdle add decoration to the gem, and increase its brilliance The standard Amencan Brilliant has 57 surfaces.

HOW IS A STONE JUDGED?

A stone submitted for evaluation is not judged on its inner flaws or inclusions which do not reach the surface, but rather on the fineness of the workmanship. First, judges look at the visual effect, noting the uniformity of facets in size, sharpness of edges, fineness of polish with no abrasions, stacking of facets above and below one another, and general consistency of overall proportions. The table must be parallel to the girdle, and the girdle line must be even and uniform in thickness. In both the crown and the pavilion, judges look for accurate meet-points where the angles come together. The crown must be aligned accurately above the pavilion. Dimensions called for in the contest directions must be precise¾ accurate to a hundredth of a millimeter.

A recent evaluation sheet contained these comments frown a judge: Sides well squared, but with non-standard dimensions (shy by one tenth of a millimeter), Superb polishing! All meet-points executed with precision and consistency; Facets brought to Table and girdle evenly and edges all sharp with no evidence of abrading; Girdle even all the way around the periphery, Culet tip is sharp, and pointed; culet facets are chisel/spade-shaped; A very nice stone¾ good demonstration of master faceting. Refer this to the Pinnacle Committee. A grade of 99.9 out of 100 points. This earned the facetor a rating of Certified Supreme Master.

ANCIENT USE OF GEMS

Often gemologists are curious about the ancient use of gems. Wright and Chadbourne in "Gems and Minerals of the Bible" claimed there were 1700 references to gemstones and minerals in the Holy Bible, under 124 Greek and Hebrew names. Of these, they described in detail 62 gems and minerals¾ from Adamant to Zircon. Not a few of those named in the ancient versions are obscure and re-identified in newer versions of the Bible.

Although Adamant is currently used to mean something very hard and unyielding, its use in the Old Testament doubtless referred to some form of corundum rather than diamond which was unknown until about 12 A.D. Gold, silver and copper were widely known from earliest time as choice minerals.

The use of agate and iron, jasper and marble was widespread. Of the gemstones, turquoise, lapis lazuli, coral, agate, jade and zircon were widely Mown among ancient peoples. The first recorded search for agate was made by the Egyptian in 3500 B. C.

1h the ancient book of Job, precious stones are compared to Wisdom:

The value of wisdom is more than coral or crystal or rubies. The finest topaz and the purest gold cannot compare with the value of wisdom. (Job 28:18 TEV).

One of the most interesting displays of gemstones was the breastplate fashioned and worn by the High Priest Aaron, brother of Moses, around 1200 B.C. Twelve stones arranged in four rows of three, have been identified in modem terms as: Red jasper, Citrine Quartz, Emerald, Ruby, Lapis Lazuli, Rock crystal (quartz), Golden sapphire, Blue sapphire, Amethyst, Yellow Jasper, Golden Beryl, Chrysoprase.

The prophet Ezekiel, writing in 586 B. C. described people in the City of Tyre as living in the garden of the Lord, and wearing gems of every }and: "rubies and diamonds; topaz, beryl, carnelian, and jasper, sapphire, emeralds and garnet; ¾ walking among sparking gems."

The New Jerusalem, described in the last book of the Bible, is said to have shone like a rare jewel, like a jasper clear as crystal. The foundation stones are listed, ¾ jasper, sapphire, agate, emerald, onyx, carnelian, quartz, beryl, topaz, chalcedony, turquoise, amethyst. The twelve gates were twelve pearls, and the streets were pure gold as clear as glass.

This Vision seems to be the answer to the earlier description of the GIRD as a Lapidary, in Isaiah, (ch 54):

O Jerusalem, you suffering helpless city wig no one to comfort you. I will build your foundations with precious stones. I will build your towers with rubies, your gates with stones that glow like fire, and the wall around you with jewels.

PRECIOUS STONES

Of all the minerals on earth, four seem to have caught the attention of He world, ¾ Platinum, gold, silver and copper. It a similar fashion of the nearly 500 gems described by Shumann in his "Gemstones of tire Work!', four have captured the world's fancy, and been labeled "Precious Stones". Among the gemstones crowding the modern jeweler's display cabinets, only four merit the term 'precious': Emerald, Sapphire, Ruby, Diamond. And since Ruby is the red form of Sapphire, that leaves just Free minerals In the 'precious' category.

Gemstones are rated for relative hardness of a scale developed by Friedrich Mohs of Vienna before 1839. He chose ten minerals of different hardness for comparison on a scale of one to ten. This scale ranges from softness like talc, which is given a One, to diamond which is given a Ten. Each mineral in the series can scratch the one below it with a pointed instrument. Quartz is given a 7, topaz 8, corundum 9, and diamond a 10. Of the precious gems, Emerald is the softest of these, with a hardness of 7 1/2 to 8; sapphire, a Nine.

EMERALD.

The name emerald comes from Greek which in turn came from Persia, and was used to refer to any green stone. Emerald belongs to the beryl group which includes aquamarine. Its chemical composition is aluminium beryllium silicate. Hardness 8. Specific gravity 2.75. Dispersion factor is low (0.014). It crystallizes in hexagonal form, as a column. Deep green is the most valuable, even though it may have inclusions of gas bubbles or foreign crystals.

Such inclusions are evidence of genuineness as compared to synthetic or imitations, and are called by experts "jardin" (garden). The most implant mines are in Columbia' South America, and were worked by the Incas, then Spaniards, sometimes forgotten until recent years. Other finds have been made in Africa, the Urals, and in the United States. Because emeralds are sensitive to knocks, the emerald cut (step cut) was developed, with four corners being truncated. Often these stones are worn in their natural crystal form.

SAPPHIRE.

Sapphire is found in many hues: black purple, green, yellow, orange, pink, blue, and clear. It has a hardness of 9, next to the diamond. Specific gravity 4.00 (much heavier than emerald). Its chemical composition is aluminium oxide and crystallizes in hexagonal form, often barrel-shaped. Its dispersion is slightly higher than emerald, 0.018. It shows definite double refraction.

Its name comes from Greek, meaning blue. In ancient times sapphire was understood as referring to lapis lastly. Around 1800 it was recognized that sapphire and its cousin ruby was a forth of corundum. Misleading names were given to the various colors, such as Oriental Topaz for the yellow. Today all colors are called by their color, i.e. yellow or green Sapphires, except the red variety called Ruby, and the orange pink called Padparadschah The coloring agents in blue sapphires are iron and titanium; chrome produces pink, vanadium, violet.. Rocks bearing this gem are marble, basalt, or pegmatite. The most important deposits are in Australia, Burma (Myanmar), Sri Lanka, Thailand, India. In 1894 deposits were discovered in Montana, these tend to be pale blue or iron blue.

Synthetic sapphires are corundum that has been heated in a furnace to form a crystal with color added. Chemically, synthetics are exactly like natural stones, and often more pure.

RUBY.

Ruby is red, of varying shades, composed of aluminium oxide, (as a sapphire) with chrome coloring. Before 1800, red spinet and games were also designated ruby. Its hardness is 9. It has no cleavage, but has certain directions for parting, and because of brittleness, care must be taken when cutting and polishing. Inclusions are common, and when cut en cabochon often show a cat's eye, or a star (called asterism). Burma, Thailand, Sri Lanka, Tanzania, Australia, Africa, Switzerland have deposits. Large rubies are often more valuable than diamonds, and have long been a part of royal jewelry.

DIAMOND.

Diamonds are colorless, yellow, brown, greenish, blue, reddish and black. Its name refers to its hardness, Adamas, which means unconquerable. Its cutting resistance is 140 times greater than corundum, its nearest rival. However, its hardbess varies on its different crystalline faces. It is not quite as heavy as sapphire, specific gravity: 3.50. Its dispersion places above all others, 0.044 without double refraction. This hardest of gems is composed of one of the softest materials ordeal carbon, like our lead pencils. It beckonsr the king of gems through a process of extreme pressure and high temperatures.

Although the diamond as a gemstone has been known far about 2,000 years, its optical properties were developed about 1400 A.D. when the hi was developed. It full potential was realized around 1910 when the full brilliant cut was developed. It now has a round girdle, 32 facets on the crown and 24 or more in the pavilion. This brilliant has 56 facets, but the Princess cut, developed in 1965 showed 146 facets. Buyers are advised to examine a diamond using the four Cs: clarity, carat weight, color, and cut. An ideal angle for cutting a modern diamond is: Crown Main angle, 34°; Pavilion Main 41°.

SYNTHETICS

Laboratory-created gems. Substitutes, imitations, man-made look-alikes have long been part of the scene. Recently I was browsing in the Glendale Galleria with my wife. A jewelry display window attracted my attention to a ring with a beautiful emerald setting, surrounded by small diamonds. Its price brought us into the store to examine it more closely. How nice it would look on my wife's fewer. With a jeweler’s glass, I noted the lack of inclusions in the green gem. Is this a real emerald?, I asked. O yes, it is marked down because it is not the fastest setting and we need to move it. Looking more closely, there was a tiny mark on the tag that indicated a "Charm Emerald". Chatham is a laboratory-created gem with a clarity and color almost too good to be true. In fact it is too good to be a true natural stone. We thanked the man for his kindness in showing the stone, and left it in his shop.

Another look-alike emerald colored stone, comes from a laboratory which took ash from Mt. St. Helens, subjected it to intense heat in a crucible and produced a piece of volcanic glass that has decorated many a piece of jewelry. It is not' however, passed off as anything other than it is. It is composed of more than twenty different minerals.

Substitutes for diamond are a frequent way to get around the high price of diamonds. Zircon, a natural stone from the Orient, Australia and Africa, is in its clear state a beautiful stone in its own right, and has a fine dispersion rate (.038). Its laboratory-created relative called cubic zirconia is more popular. It is superior to a diamond in its brillliance, has a hardness of 8 1/2, is 50% heavier than a diamond, is made in all colors. Its chemical composition is zirconia calcium-oxide. Cubic Zirconia has in recent years swept the market as an alternative to diamond.

Other man-made diamond substitutes are YAG (which is Ytrium-Aluminium-Garnet), and GGG, (gadolinium gallium garnet). Synthetic corundum is virtually identical with that found in nature and is without the inclusions¾ thus lab-grown rubies and sapphires are common.

The industry has agreed that a synthetic stone be labeled exactly as it is, and be accepted as a proper gemstone, even though it has not been pulled out of the ground. Synthetic does not mean 'imitation' or 'substitute'. It means laboratory-created.

CONCLUSION

In closing I quote from Techniques of Master Faceting", by Gerald L. Wykoff:

"Anyone can learn to facet a gemstone. Faceting isn't all that difficult.. Truth is, many of the finest faceters are self-taught. They may have mined a few stones on the way to expertise, but the techniques of surfacing a particular gem crystal with a geometrically rigid pattern of optically flat facets represents the mere tip of the iceberg.

"Faceting a gemstone isn't hard, but doing it properly with consistent good results is a different matter. The actual grinding and polishing of facets is pretty much controlled by superbly designed machines available to faceters.

"You simply can't treat a ruby as you do a garnet or an emerald or a peridot or a zircon. These are different minerals with different qualities, and the master faceter takes all these elements into mind as components of a process leading to a final faceted beauty...... Knowing and responding appropriately to each step of a sequential progression from an encrusted hunk of rough crystal through Me cleaning and preparing stages, to the planning and Renting, to the actual faceting, and to the final treatment operations is what master faceting is all about."

For me, as a lapidary, the excitement comes when the final polish is laid onto the table of a carefully cut stone, when it is released from the dopstick, when the adhesive wax is removed, and it is displayed under a brilliant clear light. Striking Beauty.. Beautiful Color. Pleasing Form. Gorgeous Sparkle. These greet the lapidary and invariably he speaks aloud to whoever may be near, ''Come and see this!"

REFERENCES

Gemstones of the World, Walter Schumann, Sterling, New York. 1979.

Fundamental Faceting. Henry B. Graves. 1977.

Rocks and Minerals, A.F.L. Deeson, Potter, New York. 1973.

Gems and Minerals of the Bible, Ruth Wright, Robert Chadbourne, Harper. 1970.

Description of Gem Materials, Glenn and Martha Vargas, Thermal CA . 1985

Faceting for Amateurs, Glenn and Martha Vargas, Thermal, CA. 1977.

Diagrams for Faceting, Glenn and Martha Vargas, Thermal, CA. 1975

Techniques of Master Faceting, Gerald Wykoff, Adams, Washington D.C. l985.

Good News Bible, Today's English Version, American Bible Society, N.Y. 1976.

Note

The Dispersion of a Stone is expressed in figures as the difference between the RED and the VIOLET refractive indices, ----- as when a 'rainbow' is displayed from light passing through a crystal. The Higher the figure, the Greater is the display of "fire" in the stone.