Gemstones with asterism (stars)

Epiasterism = use reflected light
Diasterism = use transmitted light

Most frequently seen star gemstones

- Almandine garnet (4 / 6 / 12 rays: epiasterism / diasterism)
- Beryl (6 rays: epiasterism)
- Corundum (6 / 12 rays: epiasterism)
- Diopside (4 rays (epiasterism)
- Enstatite (4 / 8 rays: epiasterism)
- Moonstone (4 rays: epiasterism)
- Quartz (4 / 6 / 12 or more: diasterism / epiasterism)

Synthetic and imitation star stones

- Corundum doublet / triplet (6 rays: epiasterism)
- Synthetic corundum (6 rays: epiasterism)
- Inscribed base star (any: epiasterism)
- Opal triplet star (6 rays: epiasterism)
- Mirror-backed quartz (4 / 6 / 12 or more: epiasterism)
- Synthetic rutile (4 ray: epiasterism)

Emerald and Other Beryls

By John Sinkankas
Chilton Book Company, Radnor, Pennsylvania, USA
1981 ISBN 0-8019-7114-4

Chilton Book Company writes:

This consummate portrait of Emerald and Other Beryls is a permanent reference for jewelers, gemological historians, mineralogists, geologists, and mineral collectors. John Sinkankas, a widely respected authority on the earth sciences, here provides a scholarly yet eminently readable monograph on every facet of beryl: cultural and natural history; structure and composition; lapidary and synthesis; and world occurrences, including gems, collector’s specimens, and the ore of the rare metal beryllium.

Beginning with Egypt 5500 years ago, the author traces the story of the dazzling emerald—from the fabled Table of Solomon to Queen Elizabeth II’s Coronation jewels—and its less renowned relatives, the pink morganite, the golden beryl and the blue aquamarine. The role of beryl in ornament, magic and medicine is a fascinating tale interwoven with history’s most compelling people and events. Together with a unique nomenclature appendix of synonyms in all languages for beryl and its varieties, this cultural archive is of special interest to historians, archeologists, linguists and students of curios lore.

In the second part, Sinkankas explores the natural history of emerald and beryl and the advances in mineralogical knowledge from antiquity, through the Christian Era, the Middle Ages, and into the highly technological modern era of exotic used for a mineral that was once considered suitable only for ornamentation. The author culled and synthesized the extensive literature of every language to bring to one volume all the significant material on crystal structure, chemical composition, physical and optical properties, and causes of color. A chapter is also devoted to cutting emerald and other beryls into jewelry stones.

Unmatched anywhere in the literature, the third part is an encyclopedic guide to major beryl deposits, with special notes on sources of fine crystal specimens and gem materials. Sinkankas has compressed a colossal amount of information into a readily accessible reference for mineralogists, geologists, mineral collectors, and gem cutters. Superbly rendered maps by the author augment the locality data.

In addition to photographs in color and black and white, the text is enhanced by line drawings and a series of unique watercolor paintings of actual crystal specimens done expressly for this book by the author.

About the Author
John Sinkankas has published eleven books on mineralogy, gemology, prospecting, and lapidary art, among them the critically acclaimed Gemstones of North America in two volumes and the popular Mineralogy for Amateurs. He has written more than 100 articles for popular and scientific journals, contributing regularly to Gems and Gemology, Journal of Gemmology, Rocks and Minerals, Gems and Minerals, Lapidary Journal and American Mineralogist.

Patience and Discipline

Forbes writes:

Mary Buffett spoke to Forbes.com about patience, discipline and Warren Buffett's pleasure dome.

Forbes.com: What's the most important lesson you've learned from Warren Buffett?
Mary Buffett: Patience and discipline. And doing something you love. So many people -- and Warren has said this -- are doing it for the money. That's really not the right reason. If you're doing something you love, you're more likely to put your all into it, and that generally equates to making money. He always says when he gets up in the morning he goes to his pleasure dome, which is his office.

Precious Stones

By Dr Max Bauer
Translated from the German by L.J.Spencer
Charles E Tuttle Company
1969 ISBN 8048-0489-3

Charles E Tuttle Company writes:

A popular account of their characters, occurrence, and application, with an introduction to their determination for mineralogists, lapidaries, and jewelers with an appendix on pearls and coral from the original edition and up-to-date material on synthetic gems and the cultured pearl.

Originally published in 1896 in Germany, Precious Stones was translated and brought up to date in 1903 prior to its publication in England. It is without doubt one of the most comprehensive studies of gems ever published.

Long out of print, Precious Stones appeared high on the list of a response made by antiquarian book dealers who were asked which books they would most like to see reprinted. Although the technology applicable to gems has made enormous strides in this century, the basic information contained in Precious Stones remain valid.

Part One is devoted to a consideration of the mineral characteristics which are of importance to the specialist in gems; a general consideration of the type of occurrence of precious stones; and material relating to the application and working of these stones.

Part Two contains a detailed account of every mineral which has been used for ornamental purposes, with special reference to precious stones.

Part Three epitomizes the characters to be relied on in determining precious stones and distinguishing them from other precious stones and from imitations.

Up-to-date information on synthetic gems and the cultured pearl is included in the appendices to the new edition.

Precious Stones deserves a place in the reference library of all professional people who are concerned with gems and mineralogy.

Chatoyant (Cat’s eye) gemstones

Most frequently seen cat’s eye gemstones

- Actinolite
- Apatite
- Beryl
- Chrysoberyl
- Diopside
- Gypsum
- Moonstone
- Quartz’s cat’s eye
- Tiger’s Eye (trade name) Quartz
- Tourmaline

Most frequently seen imitation cat’s eyes gemstones

- Cathaystone (fiberoptic glass)
- Glass
- Ulexite-base doublet
- Victoria cat’s eye (devitrified glass)
- Fire eye (chatoyant glass)

How To Separate Frequently Encountered Yellow Stones

- Visual observation: (10x lens) Look for color, luster, cut, doublet/triplet junctions, if any.

- Determine optic character: Single refractive (SR) / Double refractive (DR) / Anomalous Double refractive (ADR) / Aggregate (AGG).

- Spectrum: Many yellow stones may have diagnostic spectrum.

- Microscope: Inclusions may be diagnostic, but look for inclusions that differentiate natural and synthetic, doublet / triplet.

- Dichroscope: Different cutting orientations of natural and synthetic corundum may be revealed by dichroscope.

- Fluorescence: Look under shortwave and longwave for diagnostic colors.

- Immersion cell: Use immersion cell and high refractive index liquid to separate doublets/triplets.

- Refractometer: Confirm spectroscope reading with refractometer.

The yellow stones, which may resemble one another in appearance and values, are:

Quartz, Citrine

- Hardness: 7
- Specific gravity: 2.65
- Refractive index: 1.54 – 1.55
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.009
- Other points: Color, inclusions. Citrine may be treated. Gem quality stones are relatively clean. Common look-alikes are yellow beryl, yellow labradorite, scapolite, and glass. Standard / analytical techniques may be required to detect treatments / identify stones.

Synthetic quartz , citrine

- Hardness: 7
- Specific gravity: 2.65
- Refractive index: 1.54 – 1.55
- Optic sign: Uniaxial positive
- Birefringence: DR; 0.009
- Other points: Color, inclusions, twinning pattern. Synthetic citrine is produced by the hydrothermal process. Gem quality stones are relatively clean. Standard / analytical techniques may be required to identify stones.

Feldspar, Orthoclase

- Hardness: 6
- Specific gravity: 2.56
- Refractive index: 1.52 – 1.53
- Optic sign: Biaxial negative
- Birefringence: DR; 0.006
- Other points: Color, inclusions, cleavage. Gem quality stones are relatively clean. Common look-alikes are yellow beryl, citrine, scapolite, and glass. Standard / analytical techniques may be required to identify stones.

Feldspar, Labradorite

- Hardness: 6
- Specific gravity: 2.70 (average)
- Refractive index: 1.56 – 1.57
- Optic sign: Biaxial positive
- Birefringence: DR; 0.009
- Other points: Color, inclusions, cleavage. Gem quality stones are relatively clean. Common look-alikes are yellow beryl, citrine, scapolite, and glass. Standard / analytical techniques may be required to identify stones.

Beryl

- Hardness: 7.75
- Specific gravity: 2.70 – 2.90
- Refractive index: 1.56 – 1.59
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.005/9
- Other points: Color, inclusions. Gem quality stones are relatively clean. Yellow beryl may treated. Common look-alikes are yellow labradorite, citrine, scapolite, and glass. Standard / analytical techniques may be required to identify stones.

Scapolite

- Hardness: 6
- Specific gravity: 2.50-2.70
- Refractive index: 1.54 – 1.58
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.009 - 026
- Other points: Color, inclusions, fluorescence. Gem quality stones are relatively clean. Common look-alikes are yellow labradorite, citrine, yellow beryl, and glass. Standard / analytical techniques may be required to identify stones.

Apatite

- Hardness: 5
- Specific gravity: 3.18
- Refractive index: 1.63 – 1.64
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.002 – 0.004
- Other points: Color, inclusions, spectrum. Apatite may be treated. Gem quality stones are relatively clean. Common imitations include chrysoberyl, sapphire, tourmaline, danburite, peridot, topaz and glass. Standard / analytical techniques may be required to identify stones.

Danburite

- Hardness: 7
- Specific gravity: 3.00
- Refractive index: 1.63 – 1.64
- Optic sign: Biaxial negative
- Birefringence: DR; 0.006
- Other points: Color, inclusions, spectrum. Gem quality stones are relatively clean. Common imitations include chrysoberyl, sapphire, tourmaline, apatite, peridot, topaz and glass. Standard / analytical techniques may be required to identify stones.

Topaz

- Hardness: 8
- Specific gravity: 3.53
- Refractive index: 1.63 – 1.64
- Optic sign: Biaxial positive
- Birefringence: DR; 0.008
- Other points: Color, inclusions, cleavage. Topaz may be treated. Gem quality stones are relatively clean. Common imitations include chrysoberyl, sapphire, tourmaline, apatite, peridot, danburite and glass. Standard / analytical techniques may be required to detect treatments / identify stones.

Tourmaline

- Hardness: 7
- Specific gravity: 3.05
- Refractive index: 1.62 – 1.64
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.018
- Other points: Color, inclusions, doubling of back facets, pleochroism. Tourmaline may be treated. Gem quality stones are relatively clean. Common imitations include chrysoberyl, sapphire, topaz, apatite, peridot, danburite and glass. Standard / analytical techniques may be required to detect treatments / identify stones.

Idocrase

- Hardness: 6.5
- Specific gravity: 3.35
- Refractive index: 1.70 – 1.73
- Optic sign: Uniaxial negative / positive
- Birefringence: DR; 0.005
- Other points: Color, spectrum. Common imitations include chrysoberyl, sapphire, topaz, apatite, peridot, danburite, tourmaline, and glass. Standard / analytical techniques may be required to detect treatments / identify stones.

Grossular garnet

- Hardness: 7.25
- Specific gravity: 3.60 – 3.70
- Refractive index: 1.74 – 1.75
- Optic sign: SR
- Birefringence: -
- Other points: Color, inclusions. Gem quality stones are relatively clean. Common imitations include chrysoberyl, sapphire, topaz, apatite, peridot, danburite, tourmaline, and glass. Standard / analytical techniques may be required to detect treatments / identify stones.

Chrysoberyl

- Hardness: 8.5
- Specific gravity: 3.72
- Refractive index: 1.74 – 1.75
- Optic sign: Biaxial positive
- Birefringence: DR; 0.009
- Other points: Color, inclusions, spectrum. Chrysoberyl may be treated. Gem quality stones are relatively clean. Common imitations include idocrase, hessonite garnet, sapphire, topaz, apatite, peridot, danburite, tourmaline, and glass. Standard / analytical techniques may be required to detect treatments / identify stones.

Sapphire

- Hardness: 9
- Specific gravity: 4
- Refractive index: 1.76 – 1.77
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.008
- Other points: Color, inclusions, spectrum. Yellow sapphire may be treated. Gem quality stones are relatively clean. Common imitations include chrysoberyl, idocrase, hessonite garnet, topaz, apatite, peridot, danburite, tourmaline, and glass. Standard / analytical techniques may be required to detect treatments / identify stones.

Andradite garnet (yellow demantoid)

- Hardness: 6.5
- Specific gravity: 3.85
- Refractive index: 1.89
- Optic sign: SR
- Birefringence: -
- Other points: Color, inclusions, negative refractive index reading, spectrum, dispersion, luster. Common imitations include chrysoberyl, idocrase, sapphire, topaz, apatite, peridot, danburite, tourmaline, zircon, sphene, and glass. Standard / analytical techniques may be required to detect treatments / identify stones.

Zircon

- Hardness: 7.5
- Specific gravity: 4.69
- Refractive index: 1.93 – 1.99
- Optic sign: Uniaxial positive
- Birefringence: DR; 0.059
- Other points: Color, inclusions, doubling of back facets, spectrum, luster. Zircon may be treated. Gem quality stones are relatively clean. Common imitations include chrysoberyl, idocrase, sapphire, topaz, apatite, peridot, danburite, tourmaline, demantoid garnet, sphene and glass. Standard / analytical techniques may be required to detect treatments / identify stones.

Sphene

- Hardness: 5.5
- Specific gravity: 3.53
- Refractive index: 1.89 – 2.02
- Optic sign: Biaxial positive
- Birefringence: DR; 0.051
- Other points: Color, negative refractive index reading, dispersion, doubling of back facets, spectrum. Common imitations include chrysoberyl, idocrase, sapphire, topaz, apatite, peridot, danburite, tourmaline, zircon, demantoid garnet and glass. Standard / analytical techniques may be required to detect treatments / identify stones.

Synthetic cubic zirconia

- Hardness: 8.5
- Specific gravity: 5.65+
- Refractive index: 2.15+
- Optic sign: SR
- Birefringence: -
- Other points: Color, inclusions, negative refractive index, luster, dispersion, orange flash on the pavilion. Most gem quality stones are relatively clean. High dispersion will easily identify the stone. Standard / analytical techniques may be required to identify stones.

Diamond

- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Color, negative refractive index reading, dispersion, spectrum, inclusions. Yellow diamonds may be treated. Gem quality stones are relatively clean. Common imitations are synthetic cubic zirconia, synthetic moissanite, synthetic strontium titanate, GGG and glass. Analytical / standard techniques may be required to detect treatments / identify the stones.

Synthetic diamond

- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Color, negative refractive index reading, dispersion, spectrum, inclusions. Synthetic yellow diamonds are produced by high pressure high temperature method. Gem quality stones are relatively clean. Analytical / standard techniques may be required to identify the stones.

Glass

- Hardness: 5.5
- Specific gravity: 3.70
- Refractive index: 1.60 – 1.66
- Optic sign: SR
- Birefringence: -
- Other points: Color, soft, inclusions (gas bubbles, swirls), luster, spectrum.

Assembled Stones

Doublets / Triplets

Corundum composites (natural crown/synthetic base)
Refractive index: 1.76 – 1.77
Birefringence: DR; 0.008
Other points: Immersion (Look for differences in color and luster between the sections)

Garnet topped doublet (glass)
- Refractive index: 1.76 +
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Look for differences in color and luster between the sections, gas bubbles)

Patience And Discipline

Forbes writes:

Mary Buffett spoke to Forbes.com about patience, discipline and Warren Buffett's pleasure dome.

Forbes.com: What's the most important lesson you've learned from Warren Buffett?
Mary Buffett: Patience and discipline. And doing something you love. So many people -- and Warren has said this -- are doing it for the money. That's really not the right reason. If you're doing something you love, you're more likely to put your all into it, and that generally equates to making money. He always says when he gets up in the morning he goes to his pleasure dome, which is his office.

Color

Edited by Helen Varley
The Knapp Press, Publishers, Los Angeles
The Viking Press, Distributors, New York
1980 ISBN 0-89535-037-8

The Knapp Press writes:

Color is simply the greatest show on earth. Every moment it floods us with information and sensation, delineating everything we see—even our dreams. We use it in countless ways to express ourselves and to assess others. Color reaches the heart, mind and spirit alike. It can be the visceral thrill of scarlet uniform; the pleasure of a Picasso painting; the soul-solace of a violet twilight sky. Some 10,000,000 variations of color may be distinguished by the human eye. For sheer dynamic range, no other medium can touch it. Color is among the richest experiences our sense offer.

But what is color? To the physicist it is light; to the chemist it is dye or pigments. To the physiologist it exists only in the eye of the beholder; and to the psychologist color perception is a function of the brain. Color is universally present, yet its true nature is elusive. The attempt to comprehend it has obsessed some of the greatest minds in history; Aristotle, Newton and Goethe are among those who developed detailed color theories.

A fair measure of every civilization has been the passion and ingenuity with which it has sought and used color. The formulations of certain dyes and pigments were so jealously guarded that their disclosure was punishable by death. The dazzling rise of color technology means that we now live in an age of unprecedented ‘color plenty’. Trade and industry, advertisers and packagers, update their color research constantly, so crucial to profit is the right color. Prodigious choice has also bred more discriminating consumers, eager to learn about the many ways color can improve the quality of life.

Universally present, color is too often taken for granted, its possibilities scarcely tapped. People fall into comfortable patterns with clothes, cosmetics and décor, hesitating to expand safe, small circles of color. To them red means warmth, blue means cold. It is easier to feel than to think about. Yet the rewards of experimentation can be spectacular.

The fresh insights provided by Color help you to manage this powerful source for maximum satisfaction. By understanding how colors relate to one another, and to you personally, you can improve your appearance, and surroundings, enhance your sense of well being and do justice to your individuality.

Color is unique tool for raising your color consciousness. Never before has one volume presented the subject from such diverse angles, providing the ideal basis for both an immediate and lifelong study. Color’s bonus is the way in which the whole exceeds the sum of its very handsome parts. When the relations of physics to art to fashion to psychology gradually coalesce, your perception is enhanced as if your eyes had been reborn. Everyday sights are charged with a new, unimaginably richer, dimension. After Color your world will never look the same again.